Update cpu_map.h

[manikandan00]

No description provided.

[drf5n]

This won't work right:

  #define STEP_DDR      DDRA
  #define STEP_PORT     PORTA
  #define STEP_PIN      PINA
  #define X_STEP_BIT    54 // MEGA2560 Digital Pin 24
  #define Y_STEP_BIT    60// MEGA2560 Digital Pin 25
  #define Z_STEP_BIT    4 // MEGA2560 Digital Pin 26

The bits should be within the range 0-7 of the port, not the pin numbers.

For instance, on the mega digital pin 24 is PA2 per https://www.electronicshub.org/arduino-mega-pinout/ so it's port A, bit 2, and won't work as PORTA bit 54

[fra589]

I confirm that it will not work.
Moreover, you should not make a pull request for a modification that only interests you.