Pin shift in ATMEGA 4808

Other Hardware 3rd Party Boards
1

I made a PCB with an AtMega4808.
I’m using MegaCoreX & JTAG2UPDI (without bootloader) to program it.
I started my test with “blinking” the different I/O that I use to make sure everything is working correctly, and found a strange “offset” in the pin’s numbers:

With some of the microcontroller legs if I blink output N the corresponding pin turns on/off.
But for some I need to blink output N+2 to get pin N to turn on/off
I test the output with oscilloscope.

I use this simple updated blink code:

#define p1 7

void setup() {
  pinMode(p1, OUTPUT);
}

void loop() {
  digitalWrite(p1, HIGH);  // turn the LED on (HIGH is the voltage level)
  delay(500);                      // wait for a second
  digitalWrite(p1, LOW);  // turn the LED on (HIGH is the voltage level)
  delay(300);                      // wait for a second
}

When p1 = 7 the microcontroller pin 5 turns on/off
When p1 = 25 the microcontroller pin 25 turns on/off

Why is this so?
How should I correctly address the microcontroller pins?

2

Assuming you're using the pinout=32pin_standard, physical pin 5 is PA7 and physical pin 25 is PF5.

In variants/32pin-standard/pins_arduino.h you'll find the following mapping:

// Arduino pin macros
#define PIN_PA0 0
#define PIN_PA1 1
#define PIN_PA2 2
#define PIN_PA3 3
#define PIN_PA4 4
#define PIN_PA5 5
#define PIN_PA6 6
#define PIN_PA7 7
#define PIN_PC0 8
#define PIN_PC1 9
#define PIN_PC2 10
#define PIN_PC3 11
#define PIN_PD0 12
#define PIN_PD1 13
#define PIN_PD2 14
#define PIN_PD3 15
#define PIN_PD4 16
#define PIN_PD5 17
#define PIN_PD6 18
#define PIN_PD7 19
#define PIN_PF0 20
#define PIN_PF1 21
#define PIN_PF2 22
#define PIN_PF3 23
#define PIN_PF4 24
#define PIN_PF5 25
#define PIN_PF6 26

You can plainly see the the PIN_PA7 is #defined as 7, PIN_PF5 is defined as 25.

So when you're blinking the pin defined as 7 in the core, that maps to I/O PA7, which is on physical pin 5. Similarly, when you're blinking the pin defined as 25 in the core, tha maps to I/O PF5, which is on physical pin 25.

In short, the pin numbers used by the core have nothing at all to do with the physical pin numbers on the IC.

3

Thanks,
That was exactly what I was looking for!
I did tried to use (as written in KiCad)
#define p1 PA4
But did not know I had to use PIN_PA4