From 2cc73133c462a45e06e00629d17f5d07174dce11 Mon Sep 17 00:00:00 2001
From: kalymos <schumachernicolas@gmail.com>
Date: Tue, 24 Feb 2026 22:45:22 +0100
Subject: [PATCH] optimize digital input reading with boolean normalization

- Updated all input read macros (PIN_SQCK_READ, PIN_SUBQ_READ, etc.) to use double logical NOT (!!) operators.
- This ensures bitwise masks are normalized to a pure 0 or 1 boolean value.
- Optimization: Allows the compiler to use faster AVR branch instructions (SBIC/SBIS) and improves compatibility with direct equality tests.
- Updated inline documentation for better clarity on bitwise operations.
---
 PSNee/MCU.h     | 91 ++++++++++++++++++++++++-------------------------
 PSNee/PSNee.ino |  2 +-
 2 files changed, 45 insertions(+), 48 deletions(-)

diff --git a/PSNee/MCU.h b/PSNee/MCU.h
index 054cb64..f637433 100644
--- a/PSNee/MCU.h
+++ b/PSNee/MCU.h
@@ -49,21 +49,23 @@
 
 //******************************************************************************************************************
 
-// Example: (PIND & (1<<PIND6));
+// Example: (!!(PIND & (1<<PIND6)));
 
-// Read the state of the input pins Equivalent.
+// Read the state of the input pins with Boolean Normalization.
 
-// Create a mask by shifting the bit 1 to the left by PIND6's position (bit 6), 
-// and then apply a bitwise AND operation to read the state of the PIND6 pin. 
-// The result will be non-zero (true) if the PIND6 pin is high (1), and zero (false) if the PIND6 pin is low (0).
+// Create a mask by shifting the bit 1 to the left by PIND6's position (bit 6),
+// then apply a bitwise AND operation to read the state of the PIND6 pin.
+// Finally, apply a double logical NOT (!!) to normalize the result to 0 or 1.
+// The result will be 1 (true) if the PIND6 pin is high (1), and 0 (false) if the PIND6 pin is low (0).
 //
-// For instance, if PIND = b10101010 (binary value), the operation shifts the bit 1 to the left to create the mask 
-// (1<<PIND6) = b01000000. The AND operation between PIND and the mask checks if the 6th bit is set to 1 (high).
-// 
-// Before:  PIND = b10101010  // Initial value of PIND (register containing input pin states)
-// Mask:    (1<<PIND6) = b01000000  // Mask generated by shifting the bit 1 to the left to position PIND6
-// Operation: PIND & b01000000 = b00000000 // If PIND6 is low (0)
-// Operation: PIND & b01000000 = b01000000 // If PIND6 is high (1)
+// For instance, if PIND = b01000000 (binary value), the operation shifts the bit 1 to the left to create the mask
+// (1<<PIND6) = b01000000. The AND operation isolates the bit, and !! converts it to a pure boolean 1.
+//
+// Before: PIND = b01000000 // Initial value (PIN 6 is HIGH)
+// Mask: (1<<PIND6) = b01000000 // Mask for bit 6
+// Step 1: PIND & Mask = b01000000 (Value: 64)
+// Step 2: !64 = 0
+// Step 3: !0 = 1 // Final Normalized Result
 // 
 //******************************************************************************************************************
 
@@ -220,36 +222,34 @@
 //
 //******************************************************************************************************************
 
-
 #pragma once
 
-
 #ifdef ATmega328_168
 
-static inline void optimizePeripherals(void) {
-  // Configuring Port C (A0-A5) as Digital Inputs
-  // DDRC at 0 = Input. Ensure that the first 6 bits are 0. 
-  DDRC &= ~0x3F; 
+  static inline void optimizePeripherals(void) {
+    // Configuring Port C (A0-A5) as Digital Inputs
+    // DDRC at 0 = Input. Ensure that the first 6 bits are 0. 
+    DDRC &= ~0x3F; 
 
-  // Disable the ADC (Analog-to-Digital Converter)
-  // ADEN at 0 disables the module. PRADC at 1 disables the module's clock.
-  ADCSRA &= ~(1 << ADEN);
-  PRR    |= (1 << PRADC);
+    // Disable the ADC (Analog-to-Digital Converter)
+    // ADEN at 0 disables the module. PRADC at 1 disables the module's clock.
+    ADCSRA &= ~(1 << ADEN);
+    PRR    |= (1 << PRADC) | (1 << PRTIM2);
 
-  // Configure DIDR0 (Digital Input Disable Register)
-  // To read digitally via PINC, the bits of DIDR0 MUST be set to 0.
-  // (0 = Digital Buffer enabled)
-  DIDR0 &= ~0x3F;
+    // Configure DIDR0 (Digital Input Disable Register)
+    // To read digitally via PINC, the bits of DIDR0 MUST be set to 0.
+    // (0 = Digital Buffer enabled)
+    DIDR0 &= ~0x3F;
 
-  // Stop Timer 0 (Stops Arduino millis/micros)
-  // Setting TCCR0B to 0 stops the clock source. Setting TIMSK0 to 0 disables interrupts.
-  TCCR0B = 0;
-  //#define F TIMSK0 = 0;
+    // Stop Timer 0 (Stops Arduino millis/micros)
+    // Setting TCCR0B to 0 stops the clock source. Setting TIMSK0 to 0 disables interrupts.
+    TCCR0B = 0;
+    //#define F TIMSK0 = 0;
 
-  // Disable the Analog Comparator (Frees up resources on PD6/PD7)
-  // ACD at 1 = Comparator off.
-  ACSR |= (1 << ACD);
-}
+    // Disable the Analog Comparator (Frees up resources on PD6/PD7)
+    // ACD at 1 = Comparator off.
+    ACSR |= (1 << ACD);
+  }
 
   // Define the clock speed for the microcontroller
   #define F_CPU 16000000L
@@ -285,9 +285,9 @@ static inline void optimizePeripherals(void) {
   #define PIN_WFCK_CLEAR PORTB &= ~(1 << PB1)  // Set PORTB register to make PINB1 low
 
   // Read the state of the main input pins
-  #define PIN_SQCK_READ (PIND & (1 << PIND6))  // Check if the value of PIND6 is high (1)
-  #define PIN_SUBQ_READ (PIND & (1 << PIND7))  // Check if the value of PIND7 is high (1)
-  #define PIN_WFCK_READ (PINB & (1 << PINB1))  // Check if the value of PIND1 is high (1)
+  #define PIN_SQCK_READ (!!(PIND & (1 << PIND6)))  // Check if the value of PIND6 is high (1)
+  #define PIN_SUBQ_READ (!!(PIND & (1 << PIND7)))  // Check if the value of PIND7 is high (1)
+  #define PIN_WFCK_READ (!!(PINB & (1 << PINB1)))  // Check if the value of PIND1 is high (1)
 
   // LED pin handling (for indication)
   #ifdef LED_RUN
@@ -316,7 +316,7 @@ static inline void optimizePeripherals(void) {
     #define PIN_DX_CLEAR PORTD &= ~(1 << PD4)  // Set PORTD register to make PIND4 low
 
     // Read the input pins for the BIOS patch
-    #define PIN_AX_READ (PIND & (1 << PIND2))  // Read the state of PIND2
+    #define PIN_AX_READ (!!(PIND & (1 << PIND2)))  // Read the state of PIND2
 
     // External interrupt configuration for BIOS patch
     #define PIN_AX_INTERRUPT_ENABLE EIMSK |= (1 << INT0)  // Enable external interrupt on INT0 (PINB2)
@@ -330,7 +330,7 @@ static inline void optimizePeripherals(void) {
     // Defin PIN_AY for HIGH_PATCH
     #if defined(SCPH_3000) || defined(SCPH_1000)
       #define PIN_AY_INPUT DDRD &= ~(1 << DDD3)  // Set DDRD register to configure PIND3 as input
-      #define PIN_AY_READ (PIND & (1 << PIND3))  // Read the state of PIND3
+      #define PIN_AY_READ (!!(PIND & (1 << PIND3)))  // Read the state of PIND3
       #define PIN_AY_INTERRUPT_ENABLE EIMSK |= (1 << INT1)  // Enable external interrupt on INT1 (PINB3)
       #define PIN_AY_INTERRUPT_DISABLE EIMSK &= ~(1 << INT1)  // Disable external interrupt on INT1
       #define PIN_AY_INTERRUPT_RISING EICRA |= (1 << ISC11) | (1 << ISC10)  // Configure INT1 for rising edge trigger
@@ -338,17 +338,14 @@ static inline void optimizePeripherals(void) {
       #define PIN_AY_INTERRUPT_VECTOR INT1_vect  // Interrupt vector for INT1 (external interrupt)
     #endif
       // Handle switch input for BIOS patch
- #if defined(SCPH_7000)
-    #define PIN_SWITCH_INPUT DDRD &= ~(1 << DDD5)  // Configure PIND5 as input for switch
-    #define PIN_SWITCH_SET PORTD |= (1 << PD5)     // Set PIND5 high (enable pull-up)
-    #define PIN_SWITCH_READ (PIND & (1 << PIND5))  // Read the state of PIND5 (switch input)
- #endif
-
+    #if defined(SCPH_7000)
+      #define PIN_SWITCH_INPUT DDRD &= ~(1 << DDD5)  // Configure PIND5 as input for switch
+      #define PIN_SWITCH_SET PORTD |= (1 << PD5)     // Set PIND5 high (enable pull-up)
+      #define PIN_SWITCH_READ (!!(PIND & (1 << PIND5)))  // Read the state of PIND5 (switch input)
+    #endif
 
   #endif
 
-
-
   // #if defined(PSNEE_DEBUG_SERIAL_MONITOR)
   //   #define DEBUG_PRINT(x)     Serial.print(x)
   //   #define DEBUG_PRINTHEX(x)  Serial.print(x, HEX)
diff --git a/PSNee/PSNee.ino b/PSNee/PSNee.ino
index cd41205..6785300 100644
--- a/PSNee/PSNee.ino
+++ b/PSNee/PSNee.ino
@@ -19,7 +19,7 @@
 
    SCPH model number //  region code | region
 -------------------------------------------------------------------------------------------------*/
-//#define SCPH_xxxx  //              | Universal.
+#define SCPH_xxxx  //              | Universal.
 //#define SCPH_xxx1  //  NTSC U/C    | America.
 //#define SCPH_xxx2  //  PAL         | Europ.
 //#define SCPH_xxx3  //  NTSC J      | Asia.