From 81970c8b425b55eaed0c10959914e8256cec8873 Mon Sep 17 00:00:00 2001
From: "babintsev.lv" <babintsev.lv@mipt.ru>
Date: Tue, 21 Jul 2026 16:54:06 +0300
Subject: [PATCH] upd: new TB, sampler refactor

---
 rtl/sampler/src/sampler.sv      |  34 ++---
 rtl/sampler/tests/sampler_tb.sv | 246 ++++++++++++++++++--------------
 2 files changed, 153 insertions(+), 127 deletions(-)

diff --git a/rtl/sampler/src/sampler.sv b/rtl/sampler/src/sampler.sv
index 98f6841..5da3d81 100644
--- a/rtl/sampler/src/sampler.sv
+++ b/rtl/sampler/src/sampler.sv
@@ -13,18 +13,18 @@ module sampler
     input [31:0] smp_num,
     input request,
 
-    output logic [DATA_WIDTH*PACK_FACTOR-1:0]  m_axis_tdata,   
-    output logic                              m_axis_tvalid,  
+    output logic [DATA_WIDTH*PACK_FACTOR-1:0]  m_axis_tdata, 
+    output logic                              m_axis_tvalid,
     output logic done
 );
-
+    // WARNING: number of samples smp_num must be multiple of PACK_FACTOR
+    // Last (smp_num % PACK_FACTOR) will be lost and not transmitted
     logic [DATA_WIDTH-1:0] data_converted;
     logic [31:0] smp_num_reg, cnt_smp_num;
-    logic synced;   
+    logic synced;
     logic  [$clog2(PACK_FACTOR):0] pack_cnt;
     
     always_comb begin
-            data_converted = '0;
             if (PROCESS_MODE) begin
                 if (out_of_range) begin
                     data_converted = {~data_in[DATA_WIDTH-1], {(DATA_WIDTH-1){data_in[DATA_WIDTH-1]}}};
@@ -39,7 +39,12 @@ module sampler
                 end
             end
     end
-  
+
+    initial begin
+        synced = 0;
+        m_axis_tdata = '0;
+        m_axis_tvalid = 0;
+    end
     
     always_ff @(posedge clk_in) begin
         if (rst) begin
@@ -51,10 +56,9 @@ module sampler
             synced <= 0;
             done <= 0;
         end else begin
-            m_axis_tvalid <= 0;
             if (!synced) begin
                 if (done && request) begin
-                    synced  <= 1;
+                    synced <= 1;
                     done <= 0;
                     cnt_smp_num <= 0;
                     smp_num_reg <= smp_num;
@@ -63,23 +67,21 @@ module sampler
                 end
             end else begin
                 if (cnt_smp_num != smp_num_reg) begin
-                    cnt_smp_num <= cnt_smp_num +1;
+                    cnt_smp_num++;
                     m_axis_tdata[pack_cnt*DATA_WIDTH +: DATA_WIDTH] <= data_converted;
                     if (pack_cnt == PACK_FACTOR-1) begin
                         pack_cnt <= 0;
                         m_axis_tvalid <= 1;
                     end else begin
-                        pack_cnt <= pack_cnt + 1;
+                        pack_cnt++;
+                        m_axis_tvalid <= 0;
                     end
                 end else begin
-                    cnt_smp_num <= '0;
-                    pack_cnt    <= '0;
+                    pack_cnt <= '0;
                     synced <= 0;
-                    done <= 1;
-                    m_axis_tdata <= '0;
+                    m_axis_tvalid <= 0;
                 end
             end
         end
-    end
-    
+    end    
 endmodule
diff --git a/rtl/sampler/tests/sampler_tb.sv b/rtl/sampler/tests/sampler_tb.sv
index 07d6176..e6c9988 100644
--- a/rtl/sampler/tests/sampler_tb.sv
+++ b/rtl/sampler/tests/sampler_tb.sv
@@ -3,15 +3,17 @@
 module sampler_tb;
 
     localparam DATA_WIDTH   = 12;
-    localparam PACK_FACTOR  = 1;
+    localparam PACK_FACTOR  = 7;
     localparam PROCESS_MODE = 0;
     localparam CLK_PERIOD   = 15.3846;
+    localparam OTR_OFFSET   = 0;
 
     logic clk;
-    logic rst;
+    logic rst_dut;
+    logic rst_gen;
 
-    logic [DATA_WIDTH-1:0] data_in;
-    logic out_of_range;
+    wire [DATA_WIDTH-1:0] data_in;
+    wire out_of_range;
 
     logic [31:0] smp_num;
 
@@ -21,15 +23,13 @@ module sampler_tb;
     logic [DATA_WIDTH*PACK_FACTOR-1:0] m_axis_tdata;
     logic m_axis_tvalid;
 
-    int received_count;
-
     sampler #(
         .DATA_WIDTH  (DATA_WIDTH),
         .PACK_FACTOR (PACK_FACTOR),
         .PROCESS_MODE(PROCESS_MODE)
     ) dut (
         .clk_in       (clk),
-        .rst          (rst),
+        .rst          (rst_dut),
 
         .data_in      (data_in),
         .out_of_range (out_of_range),
@@ -54,122 +54,97 @@ module sampler_tb;
     // =====================================================
     // RESET
     // =====================================================
-    initial begin
-        rst = 1;
-        data_in = 0;
-        out_of_range = 0;
-        done = 0;
-        smp_num = 0;
-
-        repeat(5) @(posedge clk);
-        rst = 0;
-    end
-
-    // =====================================================
-    // OUTPUT COUNTER
-    // =====================================================
-    always @(posedge clk) begin
-        if (m_axis_tvalid)
-            received_count++;
-    end
+    task automatic reset_dut();
+        @(posedge clk);
+        rst_dut = 1;
+        @(posedge clk);
+        rst_dut = 0;
+    endtask
 
     // =====================================================
     // FEED DATA
     // =====================================================
-    task automatic feed_data_stream(
-        input int num_words,
-        input bit random_data,
-        input bit random_out_of_range
+    triangle_wave_gen #(
+        .DATA_WIDTH(DATA_WIDTH),
+        .OFFSET(OTR_OFFSET), // offset of bits from '0 and '1 for OTR
+        .STEP(1) // LSB bit per clock
+    ) signal_gen (
+        .clk(clk),
+        .rst(rst_gen),
+        .signal(data_in),
+        .otr(out_of_range)
     );
-        logic [DATA_WIDTH-1:0] value;
-        bit oor;
-    begin
-        value = 1;
-
-        for (int i = 0; i < num_words; i++) begin
-
-            if (random_data)
-                value = $urandom_range(1, (1<<DATA_WIDTH)-1);
-            else
-                value = value + 1;
-
-            if (random_out_of_range)
-                oor = ($urandom_range(0,3) == 0);
-            else
-                oor = 0;
-
-            data_in      = value;
-            out_of_range = oor;
-
-            @(posedge clk);
-        end
-
-        out_of_range = 0;
-    end
-    endtask
 
     // =====================================================
-    // TEST CASE
+    // TEST TASKS
     // =====================================================
     task automatic run_test_case(
-        input int n,
-        input bit random_data,
-        input bit random_out_of_range
+        input int sample_num
     );
-    begin
-        received_count = 0;
+        logic [DATA_WIDTH-1:0] input_values[$];
+        logic [DATA_WIDTH-1:0] output_values[$];
+        bit flag;
 
-        data_in = 0;
-        out_of_range = 0;
-        done = 0;
-
-        smp_num = n;
-
-        // handshake
+        // Startup sequence
+        rst_gen <= 1;
+        smp_num <= sample_num;
+        request <= 1;
         @(posedge clk);
-        done <= 1'b1;
-        wait(request == 1'b1);
-        @(posedge clk);
-        done <= 1'b0;
+        
+        // syncronize
+        while (!done)
+            @(posedge clk);
+        request <= 0;
+        
+        // Wait for sync and start signal generator
+        // while (!dut.synced)
+        //     @(posedge clk);
+        wait(dut.synced === 1);
+        rst_gen <= 0;
 
-        // wait enable
-        wait(dut.enable == 1'b1);
+        // Wait for valid data
+        fork
+            begin : stat_mon_proc
+                forever begin
+                    @(posedge clk);
+                    input_values.push_back(data_in);
+                    if (m_axis_tvalid) begin
+                        for (int i = 0; i < PACK_FACTOR; i++)
+                            output_values.push_back(m_axis_tdata[DATA_WIDTH*i +: DATA_WIDTH]);
+                    end
+                end
+            end
+        join_none
 
-        // feed data
-        feed_data_stream(n + 10, random_data, random_out_of_range);
+        // Wait until end
+        // while (dut.synced)
+        //     @(posedge clk);
+        wait(dut.synced === 0);
 
-        // wait completion
-        wait(dut.enable == 1'b0);
+        disable stat_mon_proc;
+        // Pop last input value. Signal is ahead of tdata for 1 cycle
+        input_values.pop_back();
 
-        $display("Expected smp_num=%0d Received=%0d", smp_num, received_count);
-
-        if (received_count == smp_num)
-            $display("[OK]");
-        else
-            $display("[ERROR]");
-
-        repeat(10) @(posedge clk);
-    end
-    endtask
-
-    // =====================================================
-    // RANDOM TESTS
-    // =====================================================
-    task automatic random_stress_test;
-        int n;
-    begin
-        for (int i = 0; i < 20; i++) begin
-            n = $urandom_range(5,20);
-
-            $display("\n--- TEST %0d --- n=%0d", i, n);
-
-            run_test_case(
-                n,
-                1,
-                1
-            );
+        // check data
+        if (input_values.size() != output_values.size()) begin
+            $display("[ERROR] -run_test_case- Input queue size don't equal to output queue size: %0d vs %0d", input_values.size(), output_values.size());
+            $finish;
         end
-    end
+        flag = 0;
+        for (int i = 0; i < input_values.size(); i++) begin
+            $write(" %0d", input_values[i]);
+            if (input_values[i] != output_values[i])
+                flag = 1;
+        end
+        $write("\n");
+        for (int i = 0; i < input_values.size(); i++) begin
+            $write(" %0d", output_values[i]);
+        end
+        $write("\n");
+        $display("Total: %0d", output_values.size());
+        if (flag) $display("FUCK");
+        else $display("SUCKASS");
+
     endtask
 
     // =====================================================
@@ -178,17 +153,66 @@ module sampler_tb;
     initial begin
 
         $display("\n=== BASIC TEST ===");
-        run_test_case(10, 0, 0);
 
-        $display("\n=== OUT_OF_RANGE TEST ===");
-        run_test_case(20, 1, 1);
+        rst_dut = 1;
+        rst_gen = 1;
+        smp_num = 0;
+        repeat(2) @(posedge clk);
+        rst_dut = 0;
+        repeat(2) @(posedge clk);
+
+        run_test_case(100);
+
 
         $display("\n=== RANDOM STRESS TEST ===");
-        random_stress_test();
+        // todo
 
         $display("\n=== TEST FINISHED ===");
         $finish;
 
     end
 
-endmodule
\ No newline at end of file
+endmodule
+
+module triangle_wave_gen #(
+        parameter DATA_WIDTH = 12,
+        parameter OFFSET = 100, // offset of bits from '0 and '1 for OTR
+        parameter STEP = 1 // LSB bit per clock
+    ) (
+        input clk,
+        input rst,
+        output logic [DATA_WIDTH-1:0] signal,
+        output logic otr
+    );
+    logic [DATA_WIDTH:0] counter;
+    logic direction;
+
+    initial begin
+        counter = '0;
+        direction = 1;
+    end
+
+    assign signal = counter > (2**DATA_WIDTH-1) ? (2**DATA_WIDTH-1) : counter;
+
+    always_comb begin
+        if (signal < OFFSET || (2**DATA_WIDTH - signal) <= OFFSET)
+            otr <= 1;
+        else
+            otr <= 0;
+    end
+
+    always @(posedge clk) begin
+        if (rst) begin
+            counter = 0;
+            direction = 1;
+        end else begin
+            if (direction)
+                counter += STEP;
+            else
+                counter -= STEP;
+
+            if (counter >= 2**DATA_WIDTH-1 || counter <= 0)
+                direction <= ~direction;
+        end
+    end
+endmodule