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LAB3/src/led_controller.vhd

@@ -1,37 +1,64 @@
 LIBRARY IEEE;
 USE IEEE.STD_LOGIC_1164.ALL;
 
+-- Entity: led_controller
+-- Purpose: Controls RGB LED indicators based on audio system status
+--          Provides visual feedback for mute and filter enable states
 ENTITY led_controller IS
-	GENERIC (
-		LED_WIDTH : POSITIVE := 8
-	);
-	PORT (
-		mute_enable : IN STD_LOGIC;
-		filter_enable : IN STD_LOGIC;
+    GENERIC (
+        LED_WIDTH : POSITIVE := 8  -- Width of LED intensity control (8-bit = 0-255 intensity levels)
+    );
+    PORT (
+        -- Control input signals
+        mute_enable : IN STD_LOGIC;    -- Mute status (1=audio muted, 0=audio active)
+        filter_enable : IN STD_LOGIC;  -- Filter status (1=filter active, 0=filter bypassed)
 
-		led_r : OUT STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0);
-		led_g : OUT STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0);
-		led_b : OUT STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0)
-	);
+        -- RGB LED output signals (intensity control)
+        led_r : OUT STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0);  -- Red LED intensity (0-255)
+        led_g : OUT STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0);  -- Green LED intensity (0-255)
+        led_b : OUT STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0)   -- Blue LED intensity (0-255)
+    );
 END led_controller;
 
 ARCHITECTURE Behavioral OF led_controller IS
 
-	-- constant for "ON" and "OFF"
-	CONSTANT ALL_ON : STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0) := (OTHERS => '1');
-	CONSTANT ALL_OFF : STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0) := (OTHERS => '0');
+    -- Constants for LED intensity levels
+    CONSTANT ALL_ON : STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0) := (OTHERS => '1');   -- Maximum brightness (255)
+    CONSTANT ALL_OFF : STD_LOGIC_VECTOR(LED_WIDTH - 1 DOWNTO 0) := (OTHERS => '0');  -- LED off (0)
 
 BEGIN
 
-	-- If mute_enable = '1'       Red LEDs on, others off
-	-- Else if filter_enable='1'  Blue LEDs on, others off
-	-- Else                       Green LEDs on, others off
+    -- LED Status Indication Logic:
+    -- Priority-based color coding for system status
+    -- 
+    -- Color Scheme:
+    -- RED    = Mute active (highest priority - audio completely off)
+    -- BLUE   = Filter active (medium priority - audio processing enabled)
+    -- GREEN  = Normal operation (lowest priority - audio pass-through)
 
-	led_r <= ALL_ON WHEN mute_enable = '1' ELSE
-		ALL_OFF;
-	led_b <= ALL_ON WHEN (mute_enable = '0' AND filter_enable = '1') ELSE
-		ALL_OFF;
-	led_g <= ALL_ON WHEN (mute_enable = '0' AND filter_enable = '0') ELSE
-		ALL_OFF;
+    -- Red LED Control: Indicates mute status
+    -- Turn on red LED when audio is muted, regardless of filter state
+    led_r <= ALL_ON WHEN mute_enable = '1' ELSE
+        ALL_OFF;
+
+    -- Blue LED Control: Indicates filter activation
+    -- Turn on blue LED when filter is active AND audio is not muted
+    -- Mute has higher priority than filter indication
+    led_b <= ALL_ON WHEN (mute_enable = '0' AND filter_enable = '1') ELSE
+        ALL_OFF;
+
+    -- Green LED Control: Indicates normal operation
+    -- Turn on green LED when audio is active (not muted) AND filter is disabled
+    -- This represents the default "audio pass-through" state
+    led_g <= ALL_ON WHEN (mute_enable = '0' AND filter_enable = '0') ELSE
+        ALL_OFF;
+
+    -- Truth Table for LED States:
+    -- mute_enable | filter_enable | RED | GREEN | BLUE | Status
+    -- ------------|---------------|-----|-------|------|------------------
+    --      0      |       0       |  0  |   1   |  0   | Normal (Green)
+    --      0      |       1       |  0  |   0   |  1   | Filter On (Blue)
+    --      1      |       0       |  1  |   0   |  0   | Muted (Red)
+    --      1      |       1       |  1  |   0   |  0   | Muted (Red)
 
 END Behavioral;