[En-Nut-Discussion] NutOS system timer for Mega2561

[PragmaLab]

Hello all,

due to weird timer behaviour of our freshly ported application (Mega128 ->
Mega2561), I came accross '\arch\avr\dev\ostimer.c' and discovered that no
longer Timer0 is used as the system timer but Timer2:

#if defined(MCU_AT90CAN128) || defined(MCU_ATMEGA2561)
#define TCCRx       TCCR2A
#define TCNTx       TCNT2
#define OCRx        OCR2A
#define TIFR_OCFx   _BV(OCF2A)
#define TIFR_TOVx  _BV(TOV2)
#define sig_TIMER   sig_OUTPUT_COMPARE2       <------- Mega2561 uses Timer2
#else
#define TCCRx       TCCR0
#define TCNTx       TCNT0
#define OCRx        OCR0
#define TIFR_OCFx   _BV(OCF0)
#define TIFR_TOVx  _BV(TOV0)
#define sig_TIMER   sig_OUTPUT_COMPARE0        <------ Mega128 uses Timer0

I might have missed some postings on this subject, but searching the Nut
Archives did not help me much

1) does anybody now the reason for this change (Timer0->Timer2)?
2) are there more modifications like this applied to NutOS when adding
Meag2561 support?

Thanks,

regards,

Rob van Lieshout