LAB3/src/LFO.vhd

@@ -99,7 +99,7 @@ BEGIN
                 valid_flag_stage1 <= '0';                     -- No valid data
                 last_flag_stage1 <= '0';                      -- Clear channel indicator
             ELSE
-                -- Calculate LFO period based on joystick input
+                -- Calculate LFO period based on joystick y-axis input
                 -- Joystick mapping:
                 -- 0-511: Faster than base frequency (shorter period)
                 -- 512: Base frequency (1kHz)

LAB3/src/LFO_1.vhd

@@ -1,15 +1,12 @@
 LIBRARY IEEE;
 USE IEEE.STD_LOGIC_1164.ALL;
-
--- Uncomment the following library declaration if using
--- arithmetic functions with Signed or Unsigned values
 USE IEEE.NUMERIC_STD.ALL;
 
--- Entity: LFO (Low Frequency Oscillator) - Alternative Implementation
+-- Entity: LFO_1 (Low Frequency Oscillator) - Alternative Implementation
 -- Purpose: Applies tremolo effect to audio by modulating amplitude with a triangular wave
 --          This is a simplified, single-process implementation compared to the pipelined version
 --          Provides real-time audio amplitude modulation for musical effects
-ENTITY LFO IS
+ENTITY LFO_1 IS
     GENERIC (
         CHANNEL_LENGHT : INTEGER := 24;              -- Bit width of audio samples (24-bit signed)
         JOYSTICK_LENGHT : INTEGER := 10;             -- Bit width of joystick input (10-bit = 0-1023 range)
@@ -21,9 +18,9 @@ ENTITY LFO IS
         aclk : IN STD_LOGIC;        -- Main system clock
         aresetn : IN STD_LOGIC;     -- Active-low asynchronous reset
 
-        -- LFO Control inputs
+        -- LFO_1 Control inputs
-        lfo_period : IN STD_LOGIC_VECTOR(JOYSTICK_LENGHT - 1 DOWNTO 0);  -- Controls LFO frequency (joystick Y-axis)
+        lfo_period : IN STD_LOGIC_VECTOR(JOYSTICK_LENGHT - 1 DOWNTO 0);  -- Controls LFO_1 frequency (joystick Y-axis)
-        lfo_enable : IN STD_LOGIC;                                       -- Enable/bypass LFO effect
+        lfo_enable : IN STD_LOGIC;                                       -- Enable/bypass LFO_1 effect
 
         -- Slave AXI Stream interface (audio input)
         s_axis_tvalid : IN STD_LOGIC;                                      -- Input data valid signal
@@ -37,26 +34,26 @@ ENTITY LFO IS
         m_axis_tlast : OUT STD_LOGIC;                                      -- Channel indicator passthrough
         m_axis_tready : IN STD_LOGIC                                       -- Downstream ready signal
     );
-END ENTITY LFO;
+END ENTITY LFO_1;
 
-ARCHITECTURE Behavioral OF LFO IS
+ARCHITECTURE Behavioral OF LFO_1 IS
 
-    -- LFO timing configuration constants
+    -- LFO_1 timing configuration constants
-    CONSTANT LFO_COUNTER_BASE_PERIOD_US : INTEGER := 1000; -- Base period: 1ms (1kHz base frequency)
+    CONSTANT LFO_1_COUNTER_BASE_PERIOD_US : INTEGER := 1000; -- Base period: 1ms (1kHz base frequency)
     CONSTANT ADJUSTMENT_FACTOR : INTEGER := 90;             -- Frequency adjustment sensitivity (clock cycles per joystick unit)
     CONSTANT JSTK_CENTER_VALUE : INTEGER := 2 ** (JOYSTICK_LENGHT - 1); -- Joystick center position (512 for 10-bit)
 
     -- Calculate base clock cycles for 1ms period at current clock frequency
-    CONSTANT LFO_COUNTER_BASE_CLK_CYCLES : INTEGER := LFO_COUNTER_BASE_PERIOD_US * 1000 / CLK_PERIOD_NS; -- 1ms = 100,000 clk cycles
+    CONSTANT LFO_1_COUNTER_BASE_CLK_CYCLES : INTEGER := LFO_1_COUNTER_BASE_PERIOD_US * 1000 / CLK_PERIOD_NS; -- 1ms = 100,000 clk cycles
 
     -- Calculate frequency range limits based on joystick range
-    CONSTANT LFO_CLK_CYCLES_MIN : INTEGER := LFO_COUNTER_BASE_CLK_CYCLES - ADJUSTMENT_FACTOR * (2 ** (JOYSTICK_LENGHT - 1)); -- 53,920 clk cycles (faster)
+    CONSTANT LFO_1_CLK_CYCLES_MIN : INTEGER := LFO_1_COUNTER_BASE_CLK_CYCLES - ADJUSTMENT_FACTOR * (2 ** (JOYSTICK_LENGHT - 1)); -- 53,920 clk cycles (faster)
-    CONSTANT LFO_CLK_CYCLES_MAX : INTEGER := LFO_COUNTER_BASE_CLK_CYCLES + ADJUSTMENT_FACTOR * (2 ** (JOYSTICK_LENGHT - 1) - 1); -- 145,990 clk cycles (slower)
+    CONSTANT LFO_1_CLK_CYCLES_MAX : INTEGER := LFO_1_COUNTER_BASE_CLK_CYCLES + ADJUSTMENT_FACTOR * (2 ** (JOYSTICK_LENGHT - 1) - 1); -- 145,990 clk cycles (slower)
 
-    -- LFO timing control signals
+    -- LFO_1 timing control signals
     SIGNAL step_clk_cycles_delta : INTEGER RANGE - 2 ** (JOYSTICK_LENGHT - 1) * ADJUSTMENT_FACTOR TO (2 ** (JOYSTICK_LENGHT - 1) - 1) * ADJUSTMENT_FACTOR := 0;
-    SIGNAL step_clk_cycles : INTEGER RANGE LFO_CLK_CYCLES_MIN TO LFO_CLK_CYCLES_MAX := LFO_COUNTER_BASE_CLK_CYCLES;
+    SIGNAL step_clk_cycles : INTEGER RANGE LFO_1_CLK_CYCLES_MIN TO LFO_1_CLK_CYCLES_MAX := LFO_1_COUNTER_BASE_CLK_CYCLES;
-    SIGNAL step_counter : NATURAL RANGE 0 TO LFO_CLK_CYCLES_MAX := 0;
+    SIGNAL step_counter : NATURAL RANGE 0 TO LFO_1_CLK_CYCLES_MAX := 0;
 
     -- Triangular wave generation signals
     -- Note: Using signed counter with extra bit to handle full range calculations
@@ -79,29 +76,29 @@ BEGIN
     -- Input ready logic: Ready when downstream is ready OR no valid data pending, AND not in reset
     s_axis_tready <= (m_axis_tready OR NOT m_axis_tvalid_int) AND aresetn;
 
-    -- Optimized single process for LFO timing and triangular waveform generation
+    -- Optimized single process for LFO_1 timing and triangular waveform generation
     -- This process handles both the frequency control and wave shape generation
     triangular_wave_lfo_generator : PROCESS (aclk)
     BEGIN
         IF rising_edge(aclk) THEN
 
             IF aresetn = '0' THEN
-                -- Reset LFO generator to initial state
+                -- Reset LFO_1 generator to initial state
-                step_clk_cycles <= LFO_COUNTER_BASE_CLK_CYCLES;  -- Set to base frequency
+                step_clk_cycles <= LFO_1_COUNTER_BASE_CLK_CYCLES;  -- Set to base frequency
                 step_counter <= 0;                               -- Clear timing counter
                 tri_counter <= (OTHERS => '0');                 -- Start triangular wave at zero
                 direction_up <= '1';                            -- Start counting up
 
             ELSE
-                -- Calculate LFO period based on joystick input
+                -- Calculate LFO_1 period based on joystick input
                 -- Joystick mapping:
                 -- 0-511: Faster than base frequency (shorter period, higher frequency)
                 -- 512: Base frequency (1kHz)
                 -- 513-1023: Slower than base frequency (longer period, lower frequency)
                 step_clk_cycles_delta <= (to_integer(unsigned(lfo_period)) - JSTK_CENTER_VALUE) * ADJUSTMENT_FACTOR;
-                step_clk_cycles <= LFO_COUNTER_BASE_CLK_CYCLES - step_clk_cycles_delta;
+                step_clk_cycles <= LFO_1_COUNTER_BASE_CLK_CYCLES - step_clk_cycles_delta;
 
-                -- Generate triangular wave when LFO is enabled
+                -- Generate triangular wave when LFO_1 is enabled
                 IF lfo_enable = '1' THEN
 
                     -- Clock divider: Update triangular wave at calculated rate
@@ -140,7 +137,7 @@ BEGIN
     END PROCESS triangular_wave_lfo_generator;
 
     -- AXI4-Stream handshake logic and audio processing
-    -- This process handles input/output data flow and applies the LFO modulation
+    -- This process handles input/output data flow and applies the LFO_1 modulation
     AXIS : PROCESS (aclk)
     BEGIN
         IF rising_edge(aclk) THEN
@@ -183,15 +180,15 @@ BEGIN
                 -- Data input logic: Process new audio samples when available and output is ready
                 IF s_axis_tvalid = '1' AND (m_axis_tready = '1' OR m_axis_tvalid_int = '0') THEN	
                     IF lfo_enable = '1' THEN
-                        -- Apply LFO tremolo effect: multiply audio sample by triangular wave
+                        -- Apply LFO_1 tremolo effect: multiply audio sample by triangular wave
                         -- This creates amplitude modulation (tremolo effect)
                         m_axis_tdata_temp <= signed(s_axis_tdata) * tri_counter;
                         s_axis_tlast_reg <= s_axis_tlast;         -- Register channel indicator
 
                     ELSE
-                        -- LFO disabled: pass audio through unchanged but maintain bit width
+                        -- LFO_1 disabled: pass audio through unchanged but maintain bit width
                         -- Left shift compensates for the right shift that occurs during output
-                        -- This ensures unity gain when LFO is bypassed
+                        -- This ensures unity gain when LFO_1 is bypassed
                         m_axis_tdata_temp <= shift_left(
                             resize(
                                 signed(s_axis_tdata),             -- Convert input to signed
@@ -213,14 +210,14 @@ BEGIN
 
     END PROCESS AXIS;
 
-    -- LFO Implementation Summary:
+    -- LFO_1 Implementation Summary:
     -- 1. Generates triangular wave at frequency controlled by joystick input
     -- 2. When enabled: multiplies audio samples by triangular wave (tremolo effect)
     -- 3. When disabled: passes audio through unchanged (bypass mode)
     -- 4. Uses proper AXI4-Stream handshaking for real-time audio processing
     --
     -- Tremolo Effect Characteristics:
-    -- - Frequency range: Approximately 0.1Hz to 10Hz (typical for audio LFO)
+    -- - Frequency range: Approximately 0.1Hz to 10Hz (typical for audio LFO_1)
     -- - Modulation depth: Controlled by TRIANGULAR_COUNTER_LENGHT generic
     -- - Waveform: Triangular (linear amplitude changes, smooth transitions)
     -- - Bypass capability: Clean audio passthrough when disabled

LAB3/src/all_pass_filter.vhd

@@ -5,7 +5,6 @@ USE ieee.numeric_std.ALL;
 -- Entity: all_pass_filter
 -- Purpose: A pass-through filter that maintains the same interface and timing
 --          characteristics as a moving average filter but passes data unchanged.
---          This is useful for testing or as a baseline comparison.
 ENTITY all_pass_filter IS
     GENERIC (
         TDATA_WIDTH : POSITIVE := 24  -- Width of the data bus in bits

LAB3/src/balance_controller.vhd

@@ -55,7 +55,7 @@ BEGIN
     s_axis_tready <= (m_axis_tready OR NOT m_axis_tvalid_int) AND aresetn;
 
     -- Balance calculation process
-    -- Converts balance knob position to attenuation levels for each channel
+    -- Converts joystick x-axis position to attenuation levels for each channel
     BALANCE_CALC : PROCESS (aclk)
     BEGIN
 

LAB3/src/digilent_jstk2.vhd

@@ -6,9 +6,7 @@ USE IEEE.STD_LOGIC_1164.ALL;
 --          Sends LED color commands and receives joystick/button data
 ENTITY digilent_jstk2 IS
     GENERIC (
-        DELAY_US : INTEGER := 225;          -- Delay (in microseconds) between two SPI packets
+        DELAY_US : INTEGER := 25;           -- Delay (in microseconds) between two SPI packets
-                                            -- 25us required by SPI IP-Core doesn't work,
-                                            -- it requires another SPI clock cycle
         CLKFREQ : INTEGER := 100_000_000;   -- Frequency of the aclk signal (in Hz)
         SPI_SCLKFREQ : INTEGER := 5_000     -- Frequency of the SPI SCLK clock signal (in Hz)
     );
@@ -44,9 +42,11 @@ ARCHITECTURE Behavioral OF digilent_jstk2 IS
     -- Command code for the SetLEDRGB command, see the JSTK2 datasheet
     CONSTANT CMDSETLEDRGB : STD_LOGIC_VECTOR(7 DOWNTO 0) := x"84";
 
-    -- Calculate delay in clock cycles based on microsecond delay and clock frequency
+    -- Calculate delay in clock cycles: (delay_period + 1_SPI_clock_period) * clock_frequency
-    -- Important: You MUST wait between two SPI packets (see JSTK2 datasheet and SPI IP-Core README)
+    -- Uses integer arithmetic optimized to avoid truncation by performing multiplications before divisions
-    CONSTANT DELAY_CLK_CYCLES : INTEGER := DELAY_US * (CLKFREQ / 1_000_000);
+    -- Formula: ((DELAY_US * SPI_SCLKFREQ + 1_000_000) * CLKFREQ) / (SPI_SCLKFREQ * 1_000_000)
+    -- This ensures proper timing between SPI packets as required by JSTK2 datasheet
+    CONSTANT DELAY_CLK_CYCLES : INTEGER := ((DELAY_US * SPI_SCLKFREQ + 1_000_000) * CLKFREQ) / (SPI_SCLKFREQ * 1_000_000);
 
     -- State machine type definitions
     TYPE tx_state_type IS (DELAY, SEND_CMD, SEND_RED, SEND_GREEN, SEND_BLUE, SEND_DUMMY);

LAB3/src/volume_multiplier.vhd

@@ -57,7 +57,7 @@ BEGIN
     s_axis_tready <= (m_axis_tready OR NOT m_axis_tvalid_int) AND aresetn;
 
     -- Volume to exponent conversion process
-    -- Converts joystick position to bit-shift amount for exponential volume scaling
+    -- Converts joystick y-axis position to bit-shift amount for exponential volume scaling
     PROCESS (aclk)
     BEGIN
 

LAB3/src/volume_saturator.vhd

@@ -115,10 +115,5 @@ BEGIN
     -- 3. Reduces wide multiplication results back to standard audio format
     -- 4. Provides "soft limiting" behavior for volume control
     -- 5. Ensures compatibility with downstream audio processing blocks
-    --
-    -- Without saturation, volume amplification could cause:
-    -- - Mathematical overflow leading to sign bit flips
-    -- - Severe audio distortion (crackling, popping sounds)
-    -- - Invalid audio sample values outside the representable range
 
 END Behavioral;