Extended Registers on ATMega128

Development Boards MicroMod
1

hey everyone,

i am new to the world of the ATMega processors. i am attempting to use the USART to communicate with my PC. my difficulties come with accessing the extended registers on the ATMega128 (registers $60 and above). it tells me those are invalide registers when i use the LD, ST commands, which it says you can use in the manual.

the processor is not in ATMega103 compatibility mode, it is a problem with the AVR Studio 4 compiler. any help would be much appreciate. thanks.

Caleb

2

IN/OUT are limited to registers 0-63. You can use LDS/STS to access the complete register set (bypassing the $60 limit).

3

i still get an error with it. the command i used was simple

ST UBRR0H, R16 ;0x90

the error was : Invalid Register.

I checked all the settings and i didn’t see anything that was setup. do you know of anything i could be missing?