[En-Nut-Discussion] Timer1, AT90CAN128 & NutOS

[Henrik Maier]

> -----Original Message-----
> From: en-nut-discussion-bounces at egnite.de [mailto:en-nut-discussion-
> bounces at egnite.de] On Behalf Of Harald Kipp
> 
> The AT90CAN128 is a bit different from the ATmega128, though.
> 
> 1. Due to a bug on the chip, the stack needs to be in internal RAM.
> Nut/OS handles this automatically, when you selected the right MCU.

The special stack handling option NUTMEM_STACKHEAP is not automatically
enabled for the AT90CAN128. It must be set in the configurator in addition
to the CPU selection. However NUTMEM_STACKHEAP is not required for newer
AT90CAN128 silicon from Revision D onwards. These chips are identified with
date code ? 0107.

> 2. The timer structure is different, actually similar to the ATmega256x.
> SO Nut/OS uses Timer2 for these chips, instead of Timer0 used for the
> m128. But Timer1 is OK.

A nice overview what is different can be found in Atmel's application note
"AVR096: Migrating from ATmega128 to AT90CAN128".

Henrik