diff --git a/designs/full_new_reflectometer/tests/reflectometer_and_dma/reference_model.py b/designs/full_new_reflectometer/tests/reflectometer_and_dma/reference_model.py
index e7a36e2..c51de3a 100644
--- a/designs/full_new_reflectometer/tests/reflectometer_and_dma/reference_model.py
+++ b/designs/full_new_reflectometer/tests/reflectometer_and_dma/reference_model.py
@@ -10,7 +10,6 @@ class Reference_model:
         pulse_height,
         adc_period,
         window_size,
-        start,
         DAC_DATA_WIDTH,
         ADC_DATA_WIDTH,
         PACK_FACTOR,
@@ -31,7 +30,6 @@ class Reference_model:
         self.pulse_height = pulse_height
         self.adc_period = adc_period
         self.window_size = window_size
-        self.start = start
 
         # parameters
         self.DAC_DATA_WIDTH = DAC_DATA_WIDTH
@@ -49,11 +47,127 @@ class Reference_model:
         self.window_data = []
         self.accum_data = []
 
+
     def gen_input_samples (self):
-        return
+        self.samples = []
+        DAC_ZERO = self.ZERO_LEVEL
+        ADC_ZERO = 1 << (self.ADC_DATA_WIDTH - 1)
+
+        DAC_RANGE = 5.0
+        ADC_RANGE = 1.0
+
+        GROUND_BIAS = 0.0
+        ADC_GAIN = 0.2
+
+        DAC_STEP = (2 * DAC_RANGE) / ((1 << self.DAC_DATA_WIDTH) - 1)
+        ADC_STEP = (2 * ADC_RANGE) / ((1 << self.ADC_DATA_WIDTH) - 1)
+
+        ADC_MAX = (1 << self.ADC_DATA_WIDTH) - 1
+
+        for _ in range(self.pulse_num):
+            sample_time = 0
+
+            while sample_time < self.pulse_period:
+                if sample_time < self.pulse_width:
+                    dac_code = self.pulse_height
+                else:
+                    dac_code = DAC_ZERO
+
+                voltage = (dac_code - DAC_ZERO) * DAC_STEP
+                voltage = (voltage - GROUND_BIAS) * ADC_GAIN
+
+                if voltage <= -ADC_RANGE:
+                    adc_code = 0
+                elif voltage >= ADC_RANGE:
+                    adc_code = ADC_MAX
+                else:
+                    adc_code = int(round(voltage / ADC_STEP + ADC_ZERO))
+
+                out_of_range = abs(voltage) >= ADC_RANGE #(adc_code == 0 or adc_code == ADC_MAX)
+
+                if self.PROCESS_MODE:
+                    msb = (adc_code >> (self.ADC_DATA_WIDTH - 1)) & 1
+
+                    if out_of_range:
+                        if msb:
+                            sample = (1 << self.ADC_DATA_WIDTH) - 1
+                        else:
+                            sample = 0
+
+                    else:
+                        sample = (((~msb) & 1) << (self.ADC_DATA_WIDTH - 1)) | (adc_code & ((1 << (self.ADC_DATA_WIDTH - 1)) - 1))
+
+                else:
+                    if out_of_range:
+
+                        if adc_code & (1 << (self.ADC_DATA_WIDTH - 1)):
+                            sample = (1 << self.ADC_DATA_WIDTH) - 1
+                        else:
+                            sample = 0
+
+                    else:
+                        sample = adc_code
+
+                self.samples.append(sample)
+                sample_time += self.adc_period
+
+
         
     def apply_window (self):
-        return
+        self.window_data = []
+        if self.window_size < 1:
+            raise ValueError(f"window_size must be >= 1, got {self.window_size}" )
+
+        if len(self.samples) == 0:
+            raise ValueError( "samples[] is empty. Call gen_input_samples() first." )
+
+        if len(self.samples) % self.window_size != 0:
+            raise ValueError( f"Number of samples ({len(self.samples)}) " f"is not divisible by window_size ({self.window_size})" )
         
+        accum = 0
+        cnt = 0
+
+        for sample in self.samples:
+            accum += sample
+            cnt += 1
+            if cnt == self.window_size:
+                self.window_data.append(accum)
+                accum = 0
+                cnt = 0
+
+
+
     def accumulate (self):
-        return
\ No newline at end of file
+        self.accum_data = []
+        windows_per_pulse = len(self.window_data) // self.pulse_num
+
+        if windows_per_pulse == 0:
+            raise ValueError("No windows were generated.")
+
+        if len(self.window_data) == 0:
+            raise ValueError( "window_data is empty. Call apply_window() first.")
+
+        if len(self.window_data) % self.pulse_num != 0:
+            raise ValueError( "window_data length is not divisible by pulse_num")
+        
+        for window in range(windows_per_pulse):
+            accum = 0
+
+            for pulse in range(self.pulse_num):
+
+                index = pulse * windows_per_pulse + window
+                accum += self.window_data[index]
+
+            self.accum_data.append(accum)
+            if len(self.accum_data) == windows_per_pulse:
+                print( f"[ReferenceModel] Accumulation complete: "
+            f"{self.pulse_num} pulses -> "
+            f"{windows_per_pulse} windows per pulse -> "
+            f"{len(self.accum_data)} output values.")
+    
+
+    def run(self):
+        self.gen_input_samples()
+        self.apply_window()
+        self.accumulate()
+        return self.accum_data
\ No newline at end of file