diff --git a/.gitignore b/.gitignore
index a89a8f3..fd060a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,7 @@
 .Xil
 xvlog.pb
 *vivado_pid*
+**/work/*
 
 # some generated files (they annoy me)
 update_config.tcl
diff --git a/rtl/accum/src/accum.sv b/rtl/accum/src/accum.sv
index 121acdc..b09b838 100644
--- a/rtl/accum/src/accum.sv
+++ b/rtl/accum/src/accum.sv
@@ -5,7 +5,6 @@ module accumulator
     parameter DATA_WIDTH = 12,
     parameter ACCUM_WIDTH = 32,
     parameter N_MAX = 4096,
-    parameter WINDOW_SIZE = 4,
     parameter PACKET_SIZE = 8,
     parameter READ_BATCH_SIZE =(PACKET_SIZE*8)/(ACCUM_WIDTH)
     )
@@ -17,6 +16,7 @@ module accumulator
     input start,
     input [31:0] smp_num,
     input [15:0] seq_num,
+    input [31:0] window_size,
 
     output [ACCUM_WIDTH-1:0] out_data,
     output out_valid,
@@ -26,6 +26,7 @@ module accumulator
     );
 
     logic [31:0] smp_num_reg, cnt_smp_num;
+    logic [31:0] window_size_reg;
     logic [15:0] seq_num_reg, cnt_seq_num;
     logic [15:0] cnt_addr, addra, addrb;
 
@@ -39,10 +40,6 @@ module accumulator
     logic out_valid_reg;
     logic finish_reg, finish_buf;
 
-    // registers for port b data request
-    reg req_data_b;
-    reg [15:0] req_addr_b;
-
     typedef enum logic [3:0] {
         IDLE,
         INIT_MEM,
@@ -58,18 +55,85 @@ module accumulator
     } wr_state_t;
     (* MARK_DEBUG="true" *) wr_state_t wr_state;
 
+    // One word per clock accumulation pipeline
+    // On every sum_valid in ACCUM we launch a BRAM read for cnt_addr
+    // On the next clock the saved sum_data is added to doutb and written back
+    logic accum_pipe_valid;
+    logic [15:0] accum_pipe_addr;
+    logic [ACCUM_WIDTH-1:0] accum_pipe_data;
+
+    // case smp_num // window_size == 1
+    // Then the next sequence can read the same address it is written
+    logic accum_pipe_bypass_valid;
+    logic [ACCUM_WIDTH-1:0] accum_pipe_bypass_data;
+    logic accum_done;
+
+    logic accum_accept_last;
+    logic accum_accept_last_all;
+    logic [ACCUM_WIDTH-1:0] accum_write_base;
+    logic [ACCUM_WIDTH-1:0] accum_write_value;
+
+    wire [31:0] window_size_safe = (window_size == 32'd0) ? 32'd1 : window_size;
+    wire start_accept = start && (wr_state == IDLE);
+
+    assign accum_accept_last     = (cnt_smp_num + window_size_reg >= smp_num_reg);
+    assign accum_accept_last_all = accum_accept_last && (cnt_seq_num == seq_num_reg - 1);
+    assign accum_write_base      = accum_pipe_bypass_valid ? accum_pipe_bypass_data : data_bram_out;
+    assign accum_write_value     = accum_pipe_data + accum_write_base;
+
+    // Memory controls to XPM
+    // In accumulation/init states they are driven directly from the current
+    // state and pipeline registers. That avoids an extra register stage
+    logic mem_wea;
+    logic mem_enb;
+    logic [15:0] mem_addra;
+    logic [15:0] mem_addrb;
+    logic [ACCUM_WIDTH-1:0] mem_dina;
+
+    assign mem_wea = (wr_state == INIT_MEM) ? valid_data :
+                     (wr_state == ACCUM)    ? accum_pipe_valid :
+                                              1'b0;
+
+    assign mem_addra = (wr_state == INIT_MEM) ? cnt_addr :
+                       (wr_state == ACCUM)    ? accum_pipe_addr :
+                                                addra;
+
+    assign mem_dina = (wr_state == INIT_MEM) ? data :
+                      (wr_state == ACCUM)    ? accum_write_value :
+                                               data_bram_in;
+
+    assign mem_enb = (wr_state == ACCUM) ? valid_data : enb;
+    assign mem_addrb = (wr_state == ACCUM) ? cnt_addr : addrb;
+
+    // registers for port b data request
+    reg req_data_b;
+    reg [15:0] req_addr_b;
+
     always @(posedge clk_in) begin
         if (rst) begin
             smp_num_reg <= '0;
             cnt_smp_num <= '0;
+            window_size_reg <= 32'd1;
             seq_num_reg <= '0;
             cnt_seq_num <= '0;
             cnt_addr <= '0;
+            addra <= '0;
+            addrb <= '0;
+            data_bram_in <= '0;
             wea <= 0;
             enb <= 0;
             wr_state <= IDLE;
             finish_reg <= 0;
+            finish_buf <= 0;
+            readout_begin_reg <= 0;
+            out_data_reg <= '0;
             out_valid_reg <= 0;
+            accum_pipe_valid <= 0;
+            accum_pipe_addr <= '0;
+            accum_pipe_data <= '0;
+            accum_pipe_bypass_valid <= 0;
+            accum_pipe_bypass_data <= '0;
+            accum_done <= 0;
         end else begin
             finish_buf <= finish;
 
@@ -83,83 +147,137 @@ module accumulator
                 readout_begin_reg <= 0;
                 finish_reg <= 0;
                 out_valid_reg <= 0;
+                accum_pipe_valid <= 0;
+                accum_pipe_bypass_valid <= 0;
+                accum_done <= 0;
+                cnt_smp_num <= '0;
+                cnt_seq_num <= '0;
+                cnt_addr <= '0;
+                addrb <= '0;
                 if (start) begin
                     smp_num_reg <= smp_num;
                     seq_num_reg <= seq_num;
+                    window_size_reg <= window_size_safe;
                     wr_state <= INIT_MEM;
                 end
 
             end
+
             INIT_MEM: begin
-                // first run to initialize memory with first batch of values
+                // First sequence 
                 wea <= 0;
+                enb <= 0;
+                out_valid_reg <= 0;
+                accum_pipe_valid <= 0;
+                accum_pipe_bypass_valid <= 0;
+                accum_done <= 0;
+
                 if (valid_data) begin
+                    // mem_wea/mem_addra/mem_dina do the actual write in this clock
                     data_bram_in <= data;
                     addra <= cnt_addr;
                     wea <= 1;
-                    cnt_addr <= cnt_addr + 1;
-                    cnt_smp_num <= cnt_smp_num + WINDOW_SIZE;
 
-                end
-                if (cnt_smp_num >= smp_num_reg) begin
-                    wr_state <= BEGIN_SEQ;
+                    if (cnt_smp_num + window_size_reg >= smp_num_reg) begin
+                        cnt_smp_num <= '0;
+                        cnt_addr <= '0;
+
+                        if (seq_num_reg <= 16'd1) begin
+                            cnt_seq_num <= '0;
+                            addrb <= '0;
+                            wr_state <= READOUT_START;
+                        end else begin
+                            // start further accumulation
+                            cnt_seq_num <= 16'd1;
+                            wr_state <= ACCUM;
+                        end
+                    end else begin
+                        cnt_smp_num <= cnt_smp_num + window_size_reg;
+                        cnt_addr <= cnt_addr + 1;
+                    end
                 end
 
             end
+
             BEGIN_SEQ: begin
-                // start new acc seq
+                // FIXME: unused
                 wea <= 0;
                 enb <= 0;
-                if (cnt_seq_num == seq_num_reg - 1) begin
-                    cnt_seq_num <= '0;
-                    cnt_smp_num <= '0;
-                    cnt_addr <= '0;
-                    wr_state <= READOUT_START;
-                    addrb <= '0;
-                    enb <= 0;
-                end else begin
-                    // beginning of new data sequence
-                    cnt_seq_num <= cnt_seq_num + 1;
-                    cnt_smp_num <= '0;
-                    cnt_addr <= '0;
-                    wea <= 0;
-                    addrb <= 0;
-                    wr_state <= REQ_WORD_B;
-                end
+                wr_state <= ACCUM;
             end
 
             REQ_WORD_B: begin
-                // pre-request data for port b
+                // FIXME: depr
                 wea <= 0;
-                enb <= 1;
-                addrb <= cnt_addr;
+                enb <= 0;
                 wr_state <= ACCUM;
             end
 
             ACCUM: begin
-                // sum mem+input
+                // accum pipeline
+                wea <= 0;
                 enb <= 0;
-                if (valid_data) begin
-                    addra <= cnt_addr;
+                out_valid_reg <= 0;
+
+                if (accum_pipe_valid) begin
+                    // mem_wea/mem_addra/mem_dina do the actual write this clock
+                    addra <= accum_pipe_addr;
+                    data_bram_in <= accum_write_value;
                     wea <= 1;
-                    data_bram_in <= data + data_bram_out;
-                    cnt_smp_num <= cnt_smp_num + WINDOW_SIZE;
-                    if (cnt_smp_num + WINDOW_SIZE >= smp_num_reg) begin
-                        wr_state <= BEGIN_SEQ;
+                end
+
+                if (accum_done) begin
+                    // Last input word was accepted on the previous clk
+                    accum_pipe_valid <= 0;
+                    accum_pipe_bypass_valid <= 0;
+                    cnt_smp_num <= '0;
+                    cnt_seq_num <= '0;
+                    cnt_addr <= '0;
+                    addrb <= '0;
+                    enb <= 0;
+                    wr_state <= READOUT_START;
+                end else if (valid_data) begin
+                    // mem_enb/mem_addrb launch the actual read this clock
+                    enb <= 1;
+                    addrb <= cnt_addr;
+
+                    accum_pipe_valid <= 1;
+                    accum_pipe_addr <= cnt_addr;
+                    accum_pipe_data <= data;
+
+                    // case window_size=1 && smp_num is small
+                    accum_pipe_bypass_valid <= accum_pipe_valid && (accum_pipe_addr == cnt_addr);
+                    accum_pipe_bypass_data <= accum_write_value;
+
+                    if (accum_accept_last) begin
+                        cnt_smp_num <= '0;
+                        cnt_addr <= '0;
+
+                        if (cnt_seq_num == seq_num_reg - 1) begin
+                            accum_done <= 1;
+                        end else begin
+                            cnt_seq_num <= cnt_seq_num + 1;
+                        end
                     end else begin
+                        cnt_smp_num <= cnt_smp_num + window_size_reg;
                         cnt_addr <= cnt_addr + 1;
-                        wr_state <= REQ_WORD_B;
                     end
+                end else begin
+                    accum_pipe_valid <= 0;
+                    accum_pipe_bypass_valid <= 0;
                 end
             end
+
             READOUT_START: begin
                 readout_begin_reg <= 1'b1;
                 wr_state <= READOUT_AWAIT;
                 enb <= 0;
+                wea <= 0;
             end
 
             READOUT_AWAIT: begin
-                // req await + delay for every-clock readout.
+                // req await + delay for every-clock readout
+                wea <= 0;
                 if (batch_req) begin
                     enb <= 1;
                     wr_state <= READOUT_DELAY;
@@ -173,12 +291,14 @@ module accumulator
 
             READOUT_DELAY: begin
                 // wait for mem latency
+                wea <= 0;
                 addrb <= addrb + 1;
                 wr_state <= READOUT_PUT;
             end
 
             READOUT_PUT: begin
                 // main data output
+                wea <= 0;
                 if ((addrb % READ_BATCH_SIZE) == 0) begin
                     wr_state <= READOUT_LAST;
                     enb <= 0;
@@ -190,6 +310,7 @@ module accumulator
 
             READOUT_LAST: begin
                 // last word of packet
+                wea <= 0;
                 out_valid_reg <= 0;
                 out_data_reg <= data_bram_out;
                 wr_state <= READOUT_START;
@@ -198,6 +319,7 @@ module accumulator
             FINISH: begin
                 out_valid_reg <= 0;
                 enb <= 0;
+                wea <= 0;
                 wr_state <= IDLE;
             end
 
@@ -210,12 +332,13 @@ module accumulator
     adder
     #(
         .DATA_WIDTH(DATA_WIDTH),
-        .WINDOW_SIZE(WINDOW_SIZE),
         .ACCUM_WIDTH(ACCUM_WIDTH)
     ) adder_dut
     (
         .clk_in(clk_in),
         .rst(rst),
+        .start(start_accept),
+        .window_size(window_size),
         .s_axis_tdata(s_axis_tdata),
         .s_axis_tvalid(s_axis_tvalid),
         .sum_data(data),
@@ -254,14 +377,14 @@ module accumulator
 
       .doutb(data_bram_out),
 
-      .addra(addra),
-      .addrb(addrb),
+      .addra(mem_addra),
+      .addrb(mem_addrb),
       .clka(clk_in),
       .clkb(clk_in),
-      .dina(data_bram_in),
+      .dina(mem_dina),
       .ena(1'b1),
-      .enb(enb),
-      .wea(wea)
+      .enb(mem_enb),
+      .wea(mem_wea)
    );
 
     assign readout_begin = readout_begin_reg;
diff --git a/rtl/accum/src/accum_top.sv b/rtl/accum/src/accum_top.sv
index 3ae2f62..dc788a1 100644
--- a/rtl/accum/src/accum_top.sv
+++ b/rtl/accum/src/accum_top.sv
@@ -5,7 +5,6 @@ module accumulator_top
     parameter DATA_WIDTH = 12,
     parameter ACCUM_WIDTH = 32,
     parameter N_MAX = 4096,
-    parameter WINDOW_SIZE = 65,
     parameter PACKET_SIZE = 1024,
     parameter READ_BATCH_SIZE =(PACKET_SIZE*8)/(ACCUM_WIDTH)
     )
@@ -22,6 +21,7 @@ module accumulator_top
     input start,
     input [31:0] smp_num,
     input [15:0] seq_num,
+    input [31:0] window_size,
 
     // eth signals
     input eth_clk_in,
@@ -42,36 +42,67 @@ module accumulator_top
     wire readout_begin;
     wire batch_req;
 
+    logic finish_int;
+    logic finish_int_d;
+    logic finish_pulse;
+    logic calc_active;
+    logic start_accept;
+    logic [31:0] window_size_reg;
+
+    wire [31:0] window_size_safe = (window_size == 32'd0) ? 32'd1 : window_size;
+
+    assign finish_pulse = finish_int && !finish_int_d;
+    assign start_accept = start && !calc_active;
+    assign finish = finish_int;
+
+    // Keep the top copy stable for blocks that start later than the accum itself
+    always_ff @(posedge clk_in) begin
+        if (rst) begin
+            calc_active     <= 1'b0;
+            finish_int_d    <= 1'b0;
+            window_size_reg <= 32'd1;
+        end else begin
+            finish_int_d <= finish_int;
+
+            if (start_accept) begin
+                calc_active     <= 1'b1;
+                window_size_reg <= window_size_safe;
+            end else if (finish_pulse) begin
+                calc_active <= 1'b0;
+            end
+        end
+    end
+
     accumulator #(
         .DATA_WIDTH(DATA_WIDTH),
         .ACCUM_WIDTH(ACCUM_WIDTH),
         .N_MAX(N_MAX),
-        .WINDOW_SIZE(WINDOW_SIZE),
         .PACKET_SIZE(PACKET_SIZE)
     ) accum_main (
         .clk_in(clk_in),
         .rst(rst),
         .s_axis_tdata(s_axis_tdata),
         .s_axis_tvalid(s_axis_tvalid),
-        .start(start),
+        .start(start_accept),
         .smp_num(smp_num),
         .seq_num(seq_num),
+        .window_size(window_size),
         .out_data(out_data),
         .out_valid(out_valid),
         .readout_begin(readout_begin),
         .batch_req(batch_req),
-        .finish(finish)
+        .finish(finish_int)
     );
 
     out_axis_fifo #(
         .ACCUM_WIDTH(ACCUM_WIDTH),
-        .WINDOW_SIZE(WINDOW_SIZE),
         .PACKET_SIZE(PACKET_SIZE)
     ) output_async_fifo (
         .eth_clk_in    (eth_clk_in),
         .acc_clk_in    (clk_in),
         .rst           (rst),
         .smp_num       (smp_num),
+        .window_size   (window_size_reg),
 
         .m_axis_tdata  (m_axis_tdata),
         .m_axis_tvalid (m_axis_tvalid),
@@ -87,6 +118,6 @@ module accumulator_top
         .send_req      (send_req),
 
         .batch_req     (batch_req),
-        .finish        (finish)
+        .finish        (finish_int)
     );
-endmodule
\ No newline at end of file
+endmodule
diff --git a/rtl/accum/src/adder.sv b/rtl/accum/src/adder.sv
index dd1c3c9..f457024 100644
--- a/rtl/accum/src/adder.sv
+++ b/rtl/accum/src/adder.sv
@@ -4,12 +4,13 @@
 module adder
 #(
     parameter DATA_WIDTH = 12,
-    parameter WINDOW_SIZE = 4,
     parameter ACCUM_WIDTH = 32
     )
 (
     input clk_in,
     input rst,
+    input start,
+    input [31:0] window_size,
     input [DATA_WIDTH-1:0] s_axis_tdata,
     input s_axis_tvalid,
     
@@ -20,7 +21,10 @@ module adder
     logic [ACCUM_WIDTH-1:0] accum, res;
     logic [DATA_WIDTH-1:0] axis_data;
     logic res_valid, axis_valid;
- (* MARK_DEBUG = "TRUE" *)   logic [15:0] cnt;
+    (* MARK_DEBUG = "TRUE" *) logic [31:0] cnt;
+    logic [31:0] window_size_reg;
+
+    wire [31:0] window_size_safe = (window_size == 32'd0) ? 32'd1 : window_size;
     
     always @(posedge clk_in) begin
         if (rst) begin
@@ -28,19 +32,32 @@ module adder
             cnt <= '0;
             res <= '0;
             res_valid <= 0;
+            axis_data <= '0;
+            axis_valid <= 0;
+            window_size_reg <= 32'd1;
         end else begin
             res_valid <= 0;
-            axis_data <= s_axis_tdata;
-            axis_valid <= s_axis_tvalid;
-            if ( axis_valid) begin
-                if (cnt == WINDOW_SIZE-1) begin
-                    res <= accum + axis_data;
-                    res_valid <= 1;
-                    accum <= '0;
-                    cnt <= '0;
-                end else begin
-                    accum <= accum + axis_data;
-                    cnt   <= cnt + 1;
+
+            if (start) begin
+                accum <= '0;
+                cnt <= '0;
+                res <= '0;
+                axis_data <= '0;
+                axis_valid <= 0;
+                window_size_reg <= window_size_safe;
+            end else begin
+                axis_data <= s_axis_tdata;
+                axis_valid <= s_axis_tvalid;
+                if (axis_valid) begin
+                    if (cnt == window_size_reg - 1) begin
+                        res <= accum + axis_data;
+                        res_valid <= 1;
+                        accum <= '0;
+                        cnt <= '0;
+                    end else begin
+                        accum <= accum + axis_data;
+                        cnt   <= cnt + 1;
+                    end
                 end
             end
         end
diff --git a/rtl/accum/src/out_axis_fifo.sv b/rtl/accum/src/out_axis_fifo.sv
index 0deb4f5..6ee3322 100644
--- a/rtl/accum/src/out_axis_fifo.sv
+++ b/rtl/accum/src/out_axis_fifo.sv
@@ -1,12 +1,12 @@
 module out_axis_fifo #(
     parameter ACCUM_WIDTH = 32,
-    parameter WINDOW_SIZE = 65,
     parameter PACKET_SIZE = 1024
 ) (
     input  logic                eth_clk_in,
     input  logic                acc_clk_in,
     input  logic                rst,
     input  logic [31:0]         smp_num,
+    input  logic [31:0]         window_size,
 
     // AXI stream master for output, eth_clk_in domain
     output logic [7:0]          m_axis_tdata,
@@ -85,6 +85,8 @@ module out_axis_fifo #(
     reg [31:0] wr_cnt;       // current BIT mem ptr
     reg [31:0] wr_batch_tgt; // next 'target' that should be written from batch
     reg [31:0] wr_total;     // total BITS to be sent!
+    logic [31:0] window_size_reg;
+    wire [31:0] window_size_safe = (window_size == 32'd0) ? 32'd1 : window_size;
 
     wire empty;
 
@@ -92,7 +94,7 @@ module out_axis_fifo #(
 
     // NOTE:
     // each written "acc_din" ACCUM_WIDTH word
-    // is counted as WINDOWS_SIZE samples actually
+    // is counted as window_size samples actually
     // because hw division for counters is painful
     // so we just increased the counter sizes
 
@@ -102,6 +104,7 @@ module out_axis_fifo #(
             wr_cnt          <= 32'b0;
             wr_batch_tgt    <= 32'b0;
             wr_total        <= 32'b0;
+            window_size_reg <= 32'd1;
             batch_req       <= 0;
             finish          <= 0;
             
@@ -115,6 +118,7 @@ module out_axis_fifo #(
                         wr_state <= WR_CHECK;
                         wr_total <= smp_num * ACCUM_WIDTH;
                         wr_batch_tgt <= 32'b0;
+                        window_size_reg <= window_size_safe;
                         batch_req <= 0;
                         finish <= 0;
                     end
@@ -126,9 +130,9 @@ module out_axis_fifo #(
                     if ((wr_data_count < (FIFO_WDEPTH - (PACKET_SIZE / (ACCUM_WIDTH / 8)))) && ~wr_rst_busy) begin
                         batch_req <= 1;
                         // should give us exactly PACKET_SIZE * 8 bits
-                        // multiplied by WINDOW_SIZE, because we count 
-                        // each given ACCUM_WIDTH word as WINDOWS_SIZE samples !!!
-                        wr_batch_tgt <= wr_batch_tgt + (8 * WINDOW_SIZE * PACKET_SIZE);
+                        // multiplied by window_size, because we count 
+                        // each given ACCUM_WIDTH word as window_size samples !!!
+                        wr_batch_tgt <= wr_batch_tgt + (8 * window_size_reg * PACKET_SIZE);
                         wr_state <= WR_RUN;
                     end else begin
                         batch_req <= 0;
@@ -150,8 +154,8 @@ module out_axis_fifo #(
 
                     if (din_valid) begin
                         // data supplied
-                        // count as we got WINDOW_SIZE samples
-                        wr_cnt <= wr_cnt + ACCUM_WIDTH * WINDOW_SIZE;
+                        // count as we got window_size samples
+                        wr_cnt <= wr_cnt + ACCUM_WIDTH * window_size_reg;
                     end
                 end
 
diff --git a/rtl/accum/tests/Makefile b/rtl/accum/tests/Makefile
index 45f5626..e6d2005 100644
--- a/rtl/accum/tests/Makefile
+++ b/rtl/accum/tests/Makefile
@@ -13,20 +13,24 @@ FPGA_ARCH = artix7
 
 RTL_DIR = ../src
 
+# Simulation settings
+SIM_TOP     = tb_accumulator_top
+SIM_RUNTIME ?= 10000 us
 
-include ../../../scripts/vivado.mk
+# Design sources only
+SYN_FILES += $(filter-out %_tb.sv,$(sort $(shell find $(RTL_DIR) -type f -name '*.v' -o -type f -name '*.sv')))
 
-SYN_FILES += $(sort $(shell find ../src -type f \( -name '*.v' -o -name '*.sv' \)))
+# Testbench sources. Vivado puts these into "sim_1", Questa compiles them into "work".
+TB_FILES += out_axis_fifo_tb.sv
+TB_FILES += accum_full_tb.sv
 
-XCI_FILES = $(sort $(shell find ../src -type f -name '*.xci'))
+XCI_FILES = $(sort $(shell find $(RTL_DIR) -type f -name '*.xci'))
 
 XDC_FILES += ../../../constraints/ax7a035b.xdc
 XDC_FILES += test_timing.xdc
 
-SYN_FILES += out_axis_fifo_tb.sv
-SYN_FILES += accum_full_tb.sv
-SIM_TOP = tb_accumulator_top
-
+include ../../../scripts/vivado.mk
+include ../../../scripts/questa.mk
 
 program: $(PROJECT).bit
 	echo "open_hw_manager" > program.tcl
diff --git a/rtl/accum/tests/accum_full_tb.sv b/rtl/accum/tests/accum_full_tb.sv
index f736609..cf74d81 100644
--- a/rtl/accum/tests/accum_full_tb.sv
+++ b/rtl/accum/tests/accum_full_tb.sv
@@ -5,7 +5,7 @@ module tb_accumulator_top;
     localparam DATA_WIDTH      = 12;
     localparam ACCUM_WIDTH     = 32;
     localparam N_MAX           = 4096;
-    localparam WINDOW_SIZE     = 65;
+    localparam MAX_WINDOW_SIZE = 65;
     localparam PACKET_SIZE     = 1024;
     localparam READ_BATCH_SIZE = (PACKET_SIZE*8)/ACCUM_WIDTH;
     localparam MAX_WORDS       = N_MAX;
@@ -20,6 +20,7 @@ module tb_accumulator_top;
     logic                  start;
     logic [31:0]           smp_num;
     logic [15:0]           seq_num;
+    logic [31:0]           window_size;
 
     logic                  req_ready;
     wire                   send_req;
@@ -50,7 +51,6 @@ module tb_accumulator_top;
         .DATA_WIDTH(DATA_WIDTH),
         .ACCUM_WIDTH(ACCUM_WIDTH),
         .N_MAX(N_MAX),
-        .WINDOW_SIZE(WINDOW_SIZE),
         .PACKET_SIZE(PACKET_SIZE)
     ) dut (
         .clk_in(clk_in),
@@ -60,6 +60,7 @@ module tb_accumulator_top;
         .start(start),
         .smp_num(smp_num),
         .seq_num(seq_num),
+        .window_size(window_size),
         .eth_clk_in(eth_clk_in),
         .req_ready(req_ready),
         .send_req(send_req),
@@ -104,6 +105,7 @@ module tb_accumulator_top;
         s_axis_tvalid = 1'b0;
         smp_num       = '0;
         seq_num       = '0;
+        window_size   = 32'd1;
         req_ready     = 1'b0;
         m_axis_tready = 1'b1;
         clear_scoreboard();
@@ -141,13 +143,14 @@ module tb_accumulator_top;
 
     task automatic run_test(
         input integer test_id,
+        input integer window_size_i,
         input integer seq_num_i,
         input integer smp_num_i,
         input bit     randomize_data,
         input integer base_value,
         input string  test_name
     );
-        logic [DATA_WIDTH-1:0] sample_mem [0:MAX_SEQ_NUM-1][0:(N_MAX*WINDOW_SIZE)-1];
+        logic [DATA_WIDTH-1:0] sample_mem [0:MAX_SEQ_NUM-1][0:(N_MAX*MAX_WINDOW_SIZE)-1];
         integer seq_idx;
         integer sample_idx;
         integer word_idx;
@@ -165,22 +168,25 @@ module tb_accumulator_top;
         tests_total   = tests_total + 1;
         errors_before = total_errors;
 
-        if (smp_num_i <= 0 || smp_num_i > N_MAX * WINDOW_SIZE || (smp_num_i % WINDOW_SIZE) != 0)
-            $fatal(1, "[%0s] invalid smp_num=%0d", test_name, smp_num_i);
+        if (window_size_i <= 0 || window_size_i > MAX_WINDOW_SIZE)
+            $fatal(1, "[%0s] invalid window_size=%0d", test_name, window_size_i);
+        if (smp_num_i <= 0 || smp_num_i > N_MAX * window_size_i || (smp_num_i % window_size_i) != 0)
+            $fatal(1, "[%0s] invalid smp_num=%0d for window_size=%0d", test_name, smp_num_i, window_size_i);
         if (seq_num_i <= 0 || seq_num_i > MAX_SEQ_NUM)
             $fatal(1, "[%0s] invalid seq_num=%0d", test_name, seq_num_i);
 
         $display("\n========================================");
         $display("TEST %0d: %0s", test_id, test_name);
-        $display("seq_num=%0d smp_num=%0d randomize=%0d", seq_num_i, smp_num_i, randomize_data);
+        $display("window_size=%0d seq_num=%0d smp_num=%0d randomize=%0d", window_size_i, seq_num_i, smp_num_i, randomize_data);
         $display("========================================");
 
         reset_dut();
-        smp_num   = smp_num_i;
-        seq_num   = seq_num_i;
-        req_ready = 1'b1; // приемник готов заранее
+        smp_num     = smp_num_i;
+        seq_num     = seq_num_i;
+        window_size = window_size_i;
+        req_ready   = 1'b1; // приемник готов заранее
 
-        exp_word_count   = smp_num_i / WINDOW_SIZE;
+        exp_word_count   = smp_num_i / window_size_i;
         exp_packet_count = (exp_word_count + READ_BATCH_SIZE - 1) / READ_BATCH_SIZE;
 
         for (seq_idx = 0; seq_idx < seq_num_i; seq_idx = seq_idx + 1) begin
@@ -196,8 +202,8 @@ module tb_accumulator_top;
         for (word_idx = 0; word_idx < exp_word_count; word_idx = word_idx + 1) begin
             local_sum = 0;
             for (seq_idx = 0; seq_idx < seq_num_i; seq_idx = seq_idx + 1) begin
-                for (k = 0; k < WINDOW_SIZE; k = k + 1)
-                    local_sum = local_sum + sample_mem[seq_idx][word_idx * WINDOW_SIZE + k];
+                for (k = 0; k < window_size_i; k = k + 1)
+                    local_sum = local_sum + sample_mem[seq_idx][word_idx * window_size_i + k];
             end
             expected_words[word_idx] = local_sum[ACCUM_WIDTH-1:0];
             $display("  expected[%0d] = %0d (0x%08x)", word_idx, expected_words[word_idx], expected_words[word_idx]);
@@ -318,16 +324,17 @@ module tb_accumulator_top;
 
         reset_dut();
 
-        run_test(1, 1,  1 * WINDOW_SIZE, 1'b0, 1,  "deterministic_small");
-//        $finish;
-        run_test(2, 2,  1 * WINDOW_SIZE, 1'b1, 0,  "random_seq3_smp8");
-        run_test(3, 1, 16 * WINDOW_SIZE, 1'b1, 0,  "random_seq5_smp16_multi_packet");
-        run_test(4, 2, 12 * WINDOW_SIZE, 1'b1, 0,  "random_seq7_smp12");
-        run_test(5, 4, 256 * WINDOW_SIZE, 1'b1, 0,  "random_max_smpnum");
-        run_test(6, 2, 1500 * WINDOW_SIZE, 1'b1, 0,  "random_max_smpnum2");
-        run_test(7, 20,  1 * WINDOW_SIZE, 1'b1, 0,  "random_20seq");
-        run_test(8, 20,  3 * WINDOW_SIZE, 1'b1, 0,  "random_20seqx3");
-        run_test(9, 200,  1 * WINDOW_SIZE, 1'b1, 0,  "random_200seq");
+        run_test(1,  1, 1,    1 * 1,  1'b0, 1,  "w1_deterministic_small");
+        run_test(2,  1, 2,   16 * 1,  1'b1, 0,  "w1_random_seq2_smp16");
+        run_test(3,  2, 2,   16 * 2,  1'b1, 0,  "w2_random_seq2_smp32");
+        run_test(4,  3, 1,   16 * 3,  1'b1, 0,  "w3_random_seq1_smp48");
+        run_test(5,  4, 2,   12 * 4,  1'b1, 0,  "w4_random_seq2_smp48");
+        run_test(6, 65, 4,  256 * 65, 1'b1, 0,  "w65_random_seq4_smp16640");
+        run_test(7,  2, 20,   3 * 2,  1'b1, 0,  "w2_random_20seqx3");
+        run_test(8, 65, 20,   3 * 65, 1'b1, 0,  "w65_random_20seqx3");
+        run_test(9,  1, 200,  1 * 1,  1'b1, 0,  "w1_random_200seq");
+        run_test(10,  2, 200,  2 * 1,  1'b1, 0,  "w2_random_200seq");
+        run_test(11,  65, 200,  65 * 1,  1'b1, 0,  "w1_random_200seq");
 
         $display("\n========================================");
         $display("ALL TESTS COMPLETED");
diff --git a/scripts/questa.mk b/scripts/questa.mk
new file mode 100644
index 0000000..59a0a1e
--- /dev/null
+++ b/scripts/questa.mk
@@ -0,0 +1,96 @@
+# SPDX-License-Identifier: MIT
+###################################################################
+# Questa/ModelSim simulation helper
+#
+# Expected variables from the project Makefile:
+#   SYN_FILES    - RTL sources
+#   TB_FILES     - testbench sources
+#   INC_FILES    - include files, optional
+#   SIM_TOP      - simulation top module
+#   SIM_DEFS     - defines, optional
+#   SIM_RUNTIME  - run time, for example "10000 us" or "-all"
+#
+# Useful overrides:
+#   make sim-questa XILINX_VIVADO=/opt/Xilinx/Vivado/2024.2
+#   make sim-questa-gui
+###################################################################
+
+.PHONY: sim-questa sim-questa-gui questa-clean questa-xpm-clean
+
+VLIB ?= vlib
+VMAP ?= vmap
+VLOG ?= vlog
+VSIM ?= vsim
+
+QUESTA_WORK_LIB ?= work
+QUESTA_XPM_LIB  ?= xpm
+QUESTA_DIR      ?= questa_build
+QUESTA_TRANSCRIPT ?= transcript
+XILINX_VIVADO=/tools/Xilinx/2025.1/Vivado
+SIM_RUNTIME ?= 10000 us
+QUESTA_RUN ?= run $(SIM_RUNTIME)
+
+# XPM is needed by this design because accum.sv uses xpm_memory_sdpram and
+# out_axis_fifo.sv uses xpm_fifo_async. Point XILINX_VIVADO to your Vivado
+# install if it is not already exported by settings64.sh.
+QUESTA_USE_XPM ?= 1
+
+QUESTA_XPM_SRC = \
+	$(XILINX_VIVADO)/data/ip/xpm/xpm_cdc/hdl/xpm_cdc.sv \
+	$(XILINX_VIVADO)/data/ip/xpm/xpm_memory/hdl/xpm_memory.sv \
+	$(XILINX_VIVADO)/data/ip/xpm/xpm_fifo/hdl/xpm_fifo.sv
+
+QUESTA_GLBL_SRC = $(XILINX_VIVADO)/data/verilog/src/glbl.v
+
+QUESTA_DEFS = $(foreach d,$(SIM_DEFS),+define+$(d))
+QUESTA_INC_DIRS = $(sort $(dir $(SYN_FILES) $(TB_FILES) $(INC_FILES)))
+QUESTA_INCS = $(foreach d,$(QUESTA_INC_DIRS),+incdir+$(d))
+QUESTA_LIBS = $(if $(filter 1,$(QUESTA_USE_XPM)),-L $(QUESTA_XPM_LIB),)
+QUESTA_SOURCES = $(SYN_FILES) $(TB_FILES) $(if $(wildcard $(QUESTA_GLBL_SRC)),$(QUESTA_GLBL_SRC),)
+
+QUESTA_GLBL_TOP = $(if $(wildcard $(QUESTA_GLBL_SRC)),$(QUESTA_WORK_LIB).glbl,)
+
+
+$(QUESTA_DIR):
+	mkdir -p $@
+
+$(QUESTA_DIR)/sources.f: Makefile | $(QUESTA_DIR)
+	@rm -f $@
+	@for inc in $(QUESTA_INCS); do echo $$inc >> $@; done
+	@for src in $(QUESTA_SOURCES); do echo $$src >> $@; done
+
+$(QUESTA_DIR)/xpm.stamp: | $(QUESTA_DIR)
+	@if [ "$(QUESTA_USE_XPM)" = "1" ]; then \
+		if [ -z "$(XILINX_VIVADO)" ]; then \
+			echo "ERROR: XILINX_VIVADO is not set. Source Vivado settings64.sh or pass XILINX_VIVADO=/path/to/Vivado/<version>."; \
+			exit 1; \
+		fi; \
+		for src in $(QUESTA_XPM_SRC); do \
+			if [ ! -f $$src ]; then \
+				echo "ERROR: XPM source not found: $$src"; \
+				exit 1; \
+			fi; \
+		done; \
+		$(VLIB) $(QUESTA_XPM_LIB); \
+		$(VMAP) $(QUESTA_XPM_LIB) $(QUESTA_XPM_LIB); \
+		$(VLOG) -sv -work $(QUESTA_XPM_LIB) $(QUESTA_XPM_SRC); \
+	fi
+	@touch $@
+
+$(QUESTA_DIR)/compile.stamp: $(QUESTA_DIR)/sources.f $(SYN_FILES) $(TB_FILES) $(INC_FILES) $(QUESTA_DIR)/xpm.stamp
+	$(VLIB) $(QUESTA_WORK_LIB)
+	$(VMAP) $(QUESTA_WORK_LIB) $(QUESTA_WORK_LIB)
+	$(VLOG) -sv -work $(QUESTA_WORK_LIB) $(QUESTA_DEFS) -timescale 1ns/1ps $(QUESTA_INCS) -f $(QUESTA_DIR)/sources.f
+	@touch $@
+
+sim-questa: $(QUESTA_DIR)/compile.stamp
+	$(VSIM) -c $(QUESTA_LIBS) $(QUESTA_WORK_LIB).$(SIM_TOP) $(QUESTA_GLBL_TOP) -do "$(QUESTA_RUN); quit -f"
+
+sim-questa-gui: $(QUESTA_DIR)/compile.stamp
+	$(VSIM) $(QUESTA_LIBS) -voptargs="+acc" $(QUESTA_WORK_LIB).$(SIM_TOP) $(QUESTA_GLBL_TOP)
+
+questa-clean:
+	-rm -rf $(QUESTA_DIR) $(QUESTA_WORK_LIB) $(QUESTA_TRANSCRIPT) vsim.wlf *.wlf
+
+questa-xpm-clean: questa-clean
+	-rm -rf $(QUESTA_XPM_LIB)
diff --git a/software/gui.py b/software/gui.py
new file mode 100644
index 0000000..1226f34
--- /dev/null
+++ b/software/gui.py
@@ -0,0 +1,736 @@
+# shitpost
+
+import sys
+import math
+import socket
+import platform
+
+from PyQt6 import uic
+from dataclasses import dataclass
+from PyQt6.QtCore import QProcess, QTimer
+from PyQt6.QtCore import QObject, QThread, pyqtSignal
+
+from PyQt6.QtCore import Qt
+import pyqtgraph as pg
+from PyQt6.QtWidgets import QApplication, QMainWindow
+
+
+@dataclass
+class ReflectometerConfig:
+    ip: str
+    send_port: int
+    recv_port: int
+
+    dac_bits: int
+    data_width: int
+    window_size: int
+    packet_size: int
+
+    pulse_width: int
+    pulse_period: int
+    pulse_height: int
+    pulse_num: int
+
+    adc_dac_ratio: float = 0.52
+    socket_timeout_sec: float = 2.0
+
+
+class ReflectometerWorker(QObject):
+    data_ready = pyqtSignal(list)
+    status = pyqtSignal(str)
+    error = pyqtSignal(str)
+    finished = pyqtSignal()
+
+    def __init__(self, config: ReflectometerConfig):
+        super().__init__()
+        self.config = config
+        self._stop_requested = False
+        self._sock = None
+
+    def stop(self):
+        self._stop_requested = True
+
+        if self._sock is not None:
+            try:
+                self._sock.close()
+            except OSError:
+                pass
+
+    def run(self):
+        try:
+            self._validate_config()
+
+            self.status.emit("Открытие UDP-сокета...")
+
+            self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+            self._sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            self._sock.settimeout(self.config.socket_timeout_sec)
+            self._sock.bind(("0.0.0.0", self.config.recv_port))
+
+            dest = (self.config.ip, self.config.send_port)
+
+            self.status.emit("Отправка soft reset...")
+            self._sock.sendto((0x0F00).to_bytes(2, "big"), dest)
+
+            self.status.emit("Отправка параметров...")
+            ctrl_data = self._format_ctrl_data()
+            self._sock.sendto(ctrl_data, dest)
+
+            self.status.emit("Отправка start...")
+            self._sock.sendto((0xF000).to_bytes(2, "big"), dest)
+
+            self.status.emit("Приём данных...")
+            data = self._recv_data()
+
+            if self._stop_requested:
+                self.status.emit("Операция остановлена")
+                return
+
+            self.data_ready.emit(data)
+            self.status.emit(f"Получено samples: {len(data)}")
+
+        except Exception as e:
+            if not self._stop_requested:
+                self.error.emit(str(e))
+
+        finally:
+            if self._sock is not None:
+                try:
+                    self._sock.close()
+                except OSError:
+                    pass
+
+            self.finished.emit()
+
+    def _format_ctrl_data(self) -> bytes:
+        output = bytearray()
+
+        output += 0b10001000.to_bytes(1, "little")
+
+        pulse_period_adc = (
+            int(self.config.pulse_period * self.config.adc_dac_ratio)
+            // self.config.window_size
+        ) * self.config.window_size
+
+        output += self.config.pulse_width.to_bytes(4, "little")
+        output += self.config.pulse_period.to_bytes(4, "little")
+        output += self.config.pulse_num.to_bytes(2, "little")
+        output += self.config.pulse_height.to_bytes(2, "little")
+        output += pulse_period_adc.to_bytes(4, "little")
+
+        if len(output) != 17:
+            raise ValueError("Config data should be 128 bits + 8 bit header")
+
+        return bytes(output)
+
+    def _recv_data(self) -> list[int]:
+        packet_count = math.ceil(
+            (
+                self.config.adc_dac_ratio
+                * self.config.pulse_period
+                / self.config.window_size
+                * self.config.data_width
+            )
+            / self.config.packet_size
+        )
+
+        expected_length = math.ceil(
+            self.config.adc_dac_ratio
+            * self.config.pulse_period
+            / self.config.window_size
+        )
+
+        recv_buf = []
+
+        for pkt_cnt in range(packet_count):
+            if self._stop_requested:
+                break
+
+            try:
+                packet, _ = self._sock.recvfrom(65536)
+            except socket.timeout:
+                raise TimeoutError(f"Таймаут приёма UDP-пакета #{pkt_cnt + 1}")
+
+            if len(packet) % self.config.data_width != 0:
+                raise ValueError(
+                    f"Некорректный размер UDP-пакета: {len(packet)} байт"
+                )
+
+            for i in range(0, len(packet), self.config.data_width):
+                sample = int.from_bytes(
+                    packet[i:i + self.config.data_width],
+                    "little",
+                )
+                recv_buf.append(sample)
+
+        if len(recv_buf) < expected_length:
+            raise ValueError(
+                f"Data underflow: получено {len(recv_buf)}, ожидалось {expected_length}"
+            )
+
+        return recv_buf[:expected_length - 1]
+
+    def _validate_config(self):
+        if self.config.pulse_period <= 0:
+            raise ValueError("pulse_period должен быть больше 0")
+
+        if self.config.pulse_num <= 0:
+            raise ValueError("pulse_num должен быть больше 0")
+
+        if self.config.window_size <= 0:
+            raise ValueError("window_size должен быть больше 0")
+
+        if self.config.packet_size <= 0:
+            raise ValueError("packet_size должен быть больше 0")
+
+        if self.config.data_width <= 0:
+            raise ValueError("data_width должен быть больше 0")
+
+        if self.config.pulse_period % self.config.window_size != 0:
+            raise ValueError("pulse_period должен быть кратен window_size")
+
+        if self.config.pulse_width >= 2**32 - 1:
+            raise ValueError("pulse_width слишком большой")
+
+        if self.config.pulse_period >= 2**32 - 1:
+            raise ValueError("pulse_period слишком большой")
+
+        if self.config.pulse_num >= 2**16 - 1:
+            raise ValueError("pulse_num слишком большой")
+
+        if self.config.pulse_height > 2**self.config.dac_bits - 1:
+            raise ValueError("pulse_height слишком большой")
+
+
+class MainWindow(QMainWindow):
+    def __init__(self):
+        super().__init__()
+
+        uic.loadUi("reflectometer.ui", self)
+
+        self.ping_process = None
+
+        self.ping_timeout_timer = QTimer(self)
+        self.ping_timeout_timer.setSingleShot(True)
+        self.ping_timeout_timer.timeout.connect(self.on_ping_timeout)
+
+        self.button_ping.clicked.connect(self.check_ping)
+
+        # settings
+        self.pulse_period = 0
+        self.pulse_height = 0
+        self.pulse_width = 0
+        self.pulse_num = 0
+
+        self.dac_dw = 14
+        self.adc_dw = 12
+        self.nmax = 4096
+        self.packet_size = 1024
+        self.window_size = 65
+        self.adc_dac_ration = 0.52
+        self.accum_width = 32
+
+        # setup
+
+        self.setup_pulse_controls()
+        self.setup_global_settings()
+
+        self.update_pulse_limits()
+
+        self.data = []
+
+        self.adc_dac_ratio = 0.52
+
+        self.measurement_thread = None
+        self.measurement_worker = None
+
+        self.setup_graph()
+        self.setup_network_settings()
+
+        self.button_start.clicked.connect(self.run_measurement)
+        self.button_graph_autoscale.clicked.connect(self.reset_graph_autoscale)
+
+    # ping utils
+
+    def check_ping(self):
+        ip = self.line_ip.text().strip()
+
+        if not ip:
+            self.label_ping_status.setText("set ip!!")
+            return
+
+        if "_" in self.line_ip.displayText():
+            self.label_ping_status.setText("IP invalid")
+            return
+
+        if self.ping_process is not None:
+            if self.ping_process.state() != QProcess.ProcessState.NotRunning:
+                self.label_ping_status.setText("Ping inflight")
+                return
+
+        self.label_ping_status.setText("ping...")
+        self.button_ping.setEnabled(False)
+
+        self.ping_process = QProcess(self)
+
+        self.ping_process.finished.connect(self.on_ping_finished)
+        self.ping_process.errorOccurred.connect(self.on_ping_error)
+
+        system_name = platform.system().lower()
+
+        if system_name == "windows":
+            program = "ping"
+            arguments = ["-n", "1", "-w", "2000", ip]
+        else:
+            program = "ping"
+            arguments = ["-c", "1", "-W", "2", ip]
+
+        self.ping_process.start(program, arguments)
+        # fallback
+        self.ping_timeout_timer.start(2000)
+
+    def on_ping_finished(self, exit_code, exit_status):
+        self.ping_timeout_timer.stop()
+        self.button_ping.setEnabled(True)
+
+        if exit_code == 0:
+            self.label_ping_status.setText("алё✅")
+        else:
+            self.label_ping_status.setText("не алё❌")
+
+    def on_ping_error(self):
+        self.ping_timeout_timer.stop()
+        self.button_ping.setEnabled(True)
+        self.label_ping_status.setText("ping unavail")
+
+    def on_ping_timeout(self):
+        if self.ping_process is not None:
+            if self.ping_process.state() != QProcess.ProcessState.NotRunning:
+                self.ping_process.kill()
+
+        self.button_ping.setEnabled(True)
+
+    # pulse controls
+    def setup_pulse_controls(self):
+        self._bind_slider_and_spinbox(
+            name="pulse_period",
+            slider=self.slider_pulse_period,
+            box=self.box_pulse_period,
+            normalize_value=self.normalize_pulse_period,
+        )
+
+        self._bind_slider_and_spinbox(
+            name="pulse_height",
+            slider=self.slider_pulse_height,
+            box=self.box_pulse_height,
+        )
+
+        self._bind_slider_and_spinbox(
+            name="pulse_width",
+            slider=self.slider_pulse_width,
+            box=self.box_pulse_width,
+        )
+
+        self._bind_slider_and_spinbox(
+            name="pulse_num",
+            slider=self.slider_pulse_num,
+            box=self.box_pulse_num,
+        )
+
+    def _bind_slider_and_spinbox(self, name, slider, box, normalize_value=None):
+        """
+        Связывает QSlider и QSpinBox по значению.
+        Значение автоматически записывается в self.<name>.
+        """
+
+        minimum = min(slider.minimum(), box.minimum())
+        maximum = max(slider.maximum(), box.maximum())
+
+        slider.setRange(minimum, maximum)
+        box.setRange(minimum, maximum)
+
+        def normalize(value):
+            if normalize_value is None:
+                return value
+
+            return normalize_value(value)
+
+        value = normalize(box.value())
+
+        slider.setValue(value)
+        box.setValue(value)
+        setattr(self, name, value)
+
+        def update_value(new_value):
+            new_value = normalize(new_value)
+
+            if slider.value() != new_value:
+                slider.setValue(new_value)
+
+            if box.value() != new_value:
+                box.setValue(new_value)
+
+            setattr(self, name, new_value)
+
+        slider.valueChanged.connect(update_value)
+        box.valueChanged.connect(update_value)
+
+    def normalize_pulse_period(self, value):
+        step = max(1, getattr(self, "window_size",
+                   self.box_window_size.value()))
+
+        snapped_value = round(value / step) * step
+
+        minimum = self.box_pulse_period.minimum()
+        maximum = self.box_pulse_period.maximum()
+
+        return max(minimum, min(snapped_value, maximum))
+
+    def _set_max_for_pair(self, slider, box, maximum):
+        slider.setMaximum(maximum)
+        box.setMaximum(maximum)
+
+        value = min(box.value(), maximum)
+        box.setValue(value)
+        slider.setValue(value)
+
+    def set_max_pulse_period(self, maximum):
+        self._set_max_for_pair(
+            slider=self.slider_pulse_period,
+            box=self.box_pulse_period,
+            maximum=maximum,
+        )
+        self.pulse_period = self.box_pulse_period.value()
+
+    def set_max_pulse_height(self, maximum):
+        self._set_max_for_pair(
+            slider=self.slider_pulse_height,
+            box=self.box_pulse_height,
+            maximum=maximum,
+        )
+        self.pulse_height = self.box_pulse_height.value()
+
+    def set_max_pulse_width(self, maximum):
+        self._set_max_for_pair(
+            slider=self.slider_pulse_width,
+            box=self.box_pulse_width,
+            maximum=maximum,
+        )
+        self.pulse_width = self.box_pulse_width.value()
+
+    def set_max_pulse_num(self, maximum):
+        self._set_max_for_pair(
+            slider=self.slider_pulse_num,
+            box=self.box_pulse_num,
+            maximum=maximum,
+        )
+        self.pulse_num = self.box_pulse_num.value()
+
+    # settings
+
+    def setup_global_settings(self):
+        self._bind_spinbox_setting(
+            name="dac_dw",
+            box=self.box_dac_dw,
+        )
+
+        self._bind_spinbox_setting(
+            name="adc_dw",
+            box=self.box_adc_dw,
+        )
+
+        self._bind_spinbox_setting(
+            name="nmax",
+            box=self.box_nmax,
+        )
+
+        self._bind_spinbox_setting(
+            name="window_size",
+            box=self.box_window_size,
+            after_change=self.on_window_size_changed,
+        )
+
+        self._bind_spinbox_setting(
+            name="packet_size",
+            box=self.box_packet_size,
+        )
+
+        self._bind_spinbox_setting(
+            name="adc_dac_ratio",
+            box=self.box_adc_dac_ratio,
+        )
+
+        self._bind_spinbox_setting(
+            name="accum_width",
+            box=self.box_accum_width,
+        )
+
+        self._bind_spinbox_setting(
+            name="recv_port",
+            box=self.box_recv_port,
+        )
+
+        self._bind_spinbox_setting(
+            name="send_port",
+            box=self.box_send_port,
+        )
+
+        # применяем шаг для pulse_period сразу при старте
+        self.update_pulse_period_step()
+
+    def _bind_spinbox_setting(self, name, box, after_change=None):
+        """
+        Связывает QSpinBox с полем self.<name>.
+        Например:
+        box_dac_dw -> self.dac_dw
+        box_window_size -> self.window_size
+        """
+
+        value = box.value()
+        setattr(self, name, value)
+
+        def on_value_changed(new_value):
+            setattr(self, name, new_value)
+
+            self.update_pulse_limits()
+
+            if after_change is not None:
+                after_change(new_value)
+
+        box.valueChanged.connect(on_value_changed)
+
+    def update_pulse_limits(self):
+        # re-calc limits
+
+        # nmax -> pulse_period limit
+        self.set_max_pulse_period(self.nmax * self.window_size)
+        self.set_max_pulse_width(self.nmax * self.window_size)
+        # accum_width + adc_width -> max pulse num
+
+        self.set_max_pulse_num(
+            2 ** (self.accum_width - self.adc_dw - math.ceil(math.log2(self.window_size))) - 1)
+        # dac_width -> max pulse height
+        self.set_max_pulse_height(2 ** self.dac_dw - 1)
+
+        self.slider_pulse_period.setMinimum(self.window_size)
+        self.box_pulse_period.setMinimum(self.window_size)
+
+    def on_window_size_changed(self, new_value):
+        self.update_pulse_period_step()
+
+    def update_pulse_period_step(self):
+        # set window_size step
+
+        step = max(1, self.window_size)
+
+        self.box_pulse_period.setSingleStep(step)
+        self.slider_pulse_period.setSingleStep(step)
+        self.slider_pulse_period.setPageStep(step)
+
+        self.snap_pulse_period_to_step(step)
+
+    def snap_pulse_period_to_step(self, step):
+        """
+        Подгоняет текущее значение pulse_period к ближайшему кратному window_size.
+
+        Это нужно потому, что QSlider при перетаскивании мышкой
+        всё равно может дать любое промежуточное значение.
+        """
+
+        current_value = self.box_pulse_period.value()
+
+        snapped_value = round(current_value / step) * step
+
+        minimum = self.box_pulse_period.minimum()
+        maximum = self.box_pulse_period.maximum()
+
+        snapped_value = max(minimum, min(snapped_value, maximum))
+
+        self.box_pulse_period.setValue(snapped_value)
+        self.slider_pulse_period.setValue(snapped_value)
+        self.pulse_period = snapped_value
+
+    # graph
+    def setup_graph(self):
+        self.graph_widget = pg.PlotWidget()
+        self.graph_widget.setLabel("left", "ADC value")
+        self.graph_widget.setLabel("bottom", "Sample")
+        self.graph_widget.showGrid(x=True, y=True)
+
+        self.graph_curve = self.graph_widget.plot(
+            [],
+            name="Data",
+        )
+
+        self.reference_curve = self.graph_widget.plot(
+            [],
+            name="Reference",
+        )
+
+        self.graph_layout.addWidget(self.graph_widget)
+        self.graph_curve = self.graph_widget.plot(
+            [], pen=pg.mkPen(width=2, color="b"))
+        self.reference_curve = self.graph_widget.plot(
+            [], pen=pg.mkPen(style=Qt.PenStyle.DashLine, color="g"))
+
+        self.checkbox_draw_reference.stateChanged.connect(
+            self.update_reference_graph)
+
+    def setup_network_settings(self):
+        self._bind_spinbox_setting(
+            name="recv_port",
+            box=self.box_recv_port,
+        )
+
+        self._bind_spinbox_setting(
+            name="send_port",
+            box=self.box_send_port,
+        )
+
+    def run_measurement(self):
+        if self.measurement_thread is not None:
+            if self.measurement_thread.isRunning():
+                self.set_measurement_status("Измерение выполняется")
+                return
+
+        config = self.build_reflectometer_config()
+
+        self.data = []
+        self.graph_curve.setData([])
+
+        self.measurement_thread = QThread(self)
+        self.measurement_worker = ReflectometerWorker(config)
+
+        self.measurement_worker.moveToThread(self.measurement_thread)
+
+        self.measurement_thread.started.connect(self.measurement_worker.run)
+
+        self.measurement_worker.status.connect(self.set_measurement_status)
+        self.measurement_worker.error.connect(self.on_measurement_error)
+        self.measurement_worker.data_ready.connect(self.on_data_received)
+
+        self.measurement_worker.finished.connect(self.measurement_thread.quit)
+        self.measurement_worker.finished.connect(
+            self.measurement_worker.deleteLater)
+
+        self.measurement_thread.finished.connect(
+            self.measurement_thread.deleteLater)
+        self.measurement_thread.finished.connect(self.on_measurement_finished)
+
+        self.measurement_thread.start()
+
+    def build_reflectometer_config(self) -> ReflectometerConfig:
+        ip = self.line_ip.text().strip()
+
+        if not ip:
+            raise ValueError("IP адрес не задан")
+
+        data_width = self.accum_width // 8
+
+        return ReflectometerConfig(
+            ip=ip,
+            send_port=self.send_port,
+            recv_port=self.recv_port,
+
+            dac_bits=self.dac_dw,
+            data_width=data_width,
+            window_size=self.window_size,
+            packet_size=self.packet_size,
+
+            pulse_width=self.pulse_width,
+            pulse_period=self.pulse_period,
+            pulse_height=self.pulse_height,
+            pulse_num=self.pulse_num,
+
+            adc_dac_ratio=self.adc_dac_ratio,
+        )
+
+    def on_data_received(self, data: list[int]):
+        self.data = data
+        # normalize
+        for i in range(len(data)):
+            self.data[i] /= (self.window_size * self.pulse_num)
+            self.data[i] -= 2 ** (self.adc_dw - 1) + 1
+
+        self.draw_main_graph()
+        self.update_reference_graph()
+
+        if data:
+            self.set_measurement_status(
+                f"Готово. smp: {len(data)}, min: {min(data)}, max: {max(data)}"
+            )
+        else:
+            self.set_measurement_status("Данные пустые")
+
+    def on_measurement_error(self, message: str):
+        self.set_measurement_status(f"Ошибка: {message}")
+
+    def on_measurement_finished(self):
+        self.measurement_worker = None
+        self.measurement_thread = None
+
+    def stop_measurement(self):
+        if self.measurement_worker is not None:
+            self.measurement_worker.stop()
+
+    def set_measurement_status(self, text: str):
+        self.label_status.setText(text)
+
+    def draw_main_graph(self):
+        if not self.data:
+            self.graph_curve.setData([])
+            return
+
+        x = list(range(len(self.data)))
+        self.graph_curve.setData(x, self.data)
+
+    def update_reference_graph(self):
+        """
+        Рисует или очищает эталонный график.
+        Вызывается после получения данных и при переключении checkbox_draw_reference.
+        """
+
+        if not self.checkbox_draw_reference.isChecked():
+            self.reference_curve.setData([])
+            return
+
+        if not self.data:
+            self.reference_curve.setData([])
+            return
+
+        reference_data = self.build_reference_data(len(self.data))
+
+        if not reference_data:
+            self.reference_curve.setData([])
+            return
+
+        x = list(range(len(reference_data)))
+        self.reference_curve.setData(x, reference_data)
+
+    def build_reference_data(self, length: int) -> list[int]:
+        reference = [0] * length
+
+        actual_pulse_width = round(
+            (self.pulse_width * self.adc_dac_ratio) / self.window_size)
+
+        reference[0:actual_pulse_width] = [
+            (self.pulse_height / 2 ** (self.dac_dw - self.adc_dw)) - 2 ** (self.adc_dw - 1), ] * (actual_pulse_width - 1)
+
+        return reference
+
+    def reset_graph_autoscale(self):
+        self.graph_widget.enableAutoRange(axis="xy", enable=True)
+        self.graph_widget.autoRange()
+
+
+def main():
+    app = QApplication(sys.argv)
+
+    window = MainWindow()
+    window.show()
+
+    sys.exit(app.exec())
+
+
+if __name__ == "__main__":
+    main()
diff --git a/software/reflectometer.ui b/software/reflectometer.ui
new file mode 100644
index 0000000..7822d14
--- /dev/null
+++ b/software/reflectometer.ui
@@ -0,0 +1,505 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>1023</width>
+    <height>708</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Reflectometer PREMIUM</string>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QHBoxLayout" name="horizontalLayout" stretch="4,2">
+    <item>
+     <layout class="QVBoxLayout" name="graph_layout"/>
+    </item>
+    <item>
+     <layout class="QVBoxLayout" name="settings_layout">
+      <item>
+       <widget class="QTabWidget" name="tabWidget">
+        <property name="currentIndex">
+         <number>1</number>
+        </property>
+        <widget class="QWidget" name="tab">
+         <attribute name="title">
+          <string>Настройки</string>
+         </attribute>
+         <layout class="QVBoxLayout" name="verticalLayout_2">
+          <item>
+           <widget class="QScrollArea" name="scrollArea">
+            <property name="widgetResizable">
+             <bool>true</bool>
+            </property>
+            <widget class="QWidget" name="scrollAreaWidgetContents">
+             <property name="geometry">
+              <rect>
+               <x>0</x>
+               <y>0</y>
+               <width>294</width>
+               <height>621</height>
+              </rect>
+             </property>
+             <layout class="QVBoxLayout" name="verticalLayout">
+              <item>
+               <widget class="QLabel" name="label_2">
+                <property name="font">
+                 <font>
+                  <pointsize>12</pointsize>
+                 </font>
+                </property>
+                <property name="text">
+                 <string>Аппаратные параметры</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_dac_dw">
+                <property name="suffix">
+                 <string> bits</string>
+                </property>
+                <property name="prefix">
+                 <string>DAC data width: </string>
+                </property>
+                <property name="minimum">
+                 <number>8</number>
+                </property>
+                <property name="maximum">
+                 <number>32</number>
+                </property>
+                <property name="value">
+                 <number>14</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_adc_dw">
+                <property name="suffix">
+                 <string> bits</string>
+                </property>
+                <property name="prefix">
+                 <string>ADC data width: </string>
+                </property>
+                <property name="minimum">
+                 <number>8</number>
+                </property>
+                <property name="maximum">
+                 <number>32</number>
+                </property>
+                <property name="value">
+                 <number>12</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_accum_width">
+                <property name="suffix">
+                 <string> bits</string>
+                </property>
+                <property name="prefix">
+                 <string>Accum width: </string>
+                </property>
+                <property name="minimum">
+                 <number>16</number>
+                </property>
+                <property name="maximum">
+                 <number>64</number>
+                </property>
+                <property name="singleStep">
+                 <number>8</number>
+                </property>
+                <property name="value">
+                 <number>32</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QDoubleSpinBox" name="box_adc_dac_ratio">
+                <property name="prefix">
+                 <string>ADC:DAC clk ratio: </string>
+                </property>
+                <property name="minimum">
+                 <double>0.200000000000000</double>
+                </property>
+                <property name="maximum">
+                 <double>3.000000000000000</double>
+                </property>
+                <property name="singleStep">
+                 <double>0.010000000000000</double>
+                </property>
+                <property name="value">
+                 <double>0.520000000000000</double>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_nmax">
+                <property name="prefix">
+                 <string>N Max: </string>
+                </property>
+                <property name="minimum">
+                 <number>512</number>
+                </property>
+                <property name="maximum">
+                 <number>65536</number>
+                </property>
+                <property name="value">
+                 <number>4096</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_window_size">
+                <property name="prefix">
+                 <string>Window size: </string>
+                </property>
+                <property name="minimum">
+                 <number>1</number>
+                </property>
+                <property name="maximum">
+                 <number>1024</number>
+                </property>
+                <property name="value">
+                 <number>65</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_packet_size">
+                <property name="suffix">
+                 <string> bytes</string>
+                </property>
+                <property name="prefix">
+                 <string>Packet size: </string>
+                </property>
+                <property name="minimum">
+                 <number>1</number>
+                </property>
+                <property name="maximum">
+                 <number>1572</number>
+                </property>
+                <property name="value">
+                 <number>1024</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="Line" name="line_2">
+                <property name="orientation">
+                 <enum>Qt::Orientation::Horizontal</enum>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLabel" name="label">
+                <property name="font">
+                 <font>
+                  <pointsize>12</pointsize>
+                 </font>
+                </property>
+                <property name="text">
+                 <string>Подключение</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLabel" name="label_3">
+                <property name="text">
+                 <string>IP устройства:</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLineEdit" name="line_ip">
+                <property name="inputMask">
+                 <string>999.999.999.999</string>
+                </property>
+                <property name="text">
+                 <string>192.168.0.2</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLabel" name="label_4">
+                <property name="text">
+                 <string>Порт отправки:</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_send_port">
+                <property name="minimum">
+                 <number>80</number>
+                </property>
+                <property name="maximum">
+                 <number>65536</number>
+                </property>
+                <property name="value">
+                 <number>8080</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLabel" name="label_5">
+                <property name="text">
+                 <string>Порт приёма:</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QSpinBox" name="box_recv_port">
+                <property name="minimum">
+                 <number>80</number>
+                </property>
+                <property name="maximum">
+                 <number>65536</number>
+                </property>
+                <property name="value">
+                 <number>8080</number>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLabel" name="label_6">
+                <property name="font">
+                 <font>
+                  <pointsize>12</pointsize>
+                 </font>
+                </property>
+                <property name="text">
+                 <string>Тест</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QPushButton" name="button_ping">
+                <property name="text">
+                 <string>алё</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QLabel" name="label_ping_status">
+                <property name="text">
+                 <string>...</string>
+                </property>
+                <property name="alignment">
+                 <set>Qt::AlignmentFlag::AlignCenter</set>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <spacer name="verticalSpacer">
+                <property name="orientation">
+                 <enum>Qt::Orientation::Vertical</enum>
+                </property>
+                <property name="sizeHint" stdset="0">
+                 <size>
+                  <width>20</width>
+                  <height>40</height>
+                 </size>
+                </property>
+               </spacer>
+              </item>
+             </layout>
+            </widget>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+        <widget class="QWidget" name="tab_2">
+         <attribute name="title">
+          <string>Управление</string>
+         </attribute>
+         <layout class="QVBoxLayout" name="verticalLayout_3">
+          <item>
+           <widget class="QLabel" name="label_7">
+            <property name="font">
+             <font>
+              <pointsize>12</pointsize>
+             </font>
+            </property>
+            <property name="text">
+             <string>Импульс</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_2" stretch="1,1,2">
+            <item>
+             <widget class="QLabel" name="label_8">
+              <property name="text">
+               <string>Период</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QSpinBox" name="box_pulse_period">
+              <property name="minimum">
+               <number>1</number>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QSlider" name="slider_pulse_period">
+              <property name="orientation">
+               <enum>Qt::Orientation::Horizontal</enum>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_3" stretch="1,1,2">
+            <item>
+             <widget class="QLabel" name="label_9">
+              <property name="text">
+               <string>Ширина</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QSpinBox" name="box_pulse_width"/>
+            </item>
+            <item>
+             <widget class="QSlider" name="slider_pulse_width">
+              <property name="orientation">
+               <enum>Qt::Orientation::Horizontal</enum>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_4" stretch="1,1,2">
+            <item>
+             <widget class="QLabel" name="label_10">
+              <property name="text">
+               <string>Высота</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QSpinBox" name="box_pulse_height"/>
+            </item>
+            <item>
+             <widget class="QSlider" name="slider_pulse_height">
+              <property name="orientation">
+               <enum>Qt::Orientation::Horizontal</enum>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_5" stretch="1,1,2">
+            <item>
+             <widget class="QLabel" name="label_11">
+              <property name="text">
+               <string>Количество</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QSpinBox" name="box_pulse_num">
+              <property name="minimum">
+               <number>1</number>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QSlider" name="slider_pulse_num">
+              <property name="minimum">
+               <number>1</number>
+              </property>
+              <property name="orientation">
+               <enum>Qt::Orientation::Horizontal</enum>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <widget class="QPushButton" name="button_start">
+            <property name="text">
+             <string>start!</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_6" stretch="1,3">
+            <item>
+             <widget class="QLabel" name="label_13">
+              <property name="font">
+               <font>
+                <bold>true</bold>
+               </font>
+              </property>
+              <property name="text">
+               <string>Статус:</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QLabel" name="label_status">
+              <property name="text">
+               <string>-</string>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <widget class="QCheckBox" name="checkbox_draw_reference">
+            <property name="text">
+             <string>Отрисовка эталона</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <spacer name="verticalSpacer_2">
+            <property name="orientation">
+             <enum>Qt::Orientation::Vertical</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>20</width>
+              <height>40</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+          <item>
+           <widget class="QPushButton" name="button_graph_autoscale">
+            <property name="text">
+             <string>Сброс масштаба</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+       </widget>
+      </item>
+     </layout>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menubar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>1023</width>
+     <height>30</height>
+    </rect>
+   </property>
+  </widget>
+  <widget class="QStatusBar" name="statusbar"/>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>