ATXMEGA - USART flags ?

kulisek · Joined: 04 Jul 2006 Posts: 51

Hi,

How can I read Frame error "FERR" flag in ASM for Atxmega ?

For Atmega works this

SBRC Uart_status,fe0

but for Atxmega this does not work

SBRC Uart_status,USARTC0_STATUS.4

Thanks

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

it is better to code it in basic. after all this is the bascom-avr forum.

The problem with asm is that it is different depending on the chip. the compiler handles this automatic.
if you use asm, you can not port your code simple to a different chip.
normally, adjusting the $regfile is sufficient.
but if you include asm, you can not port.

you can use bitwait to wait for a bit state.
of course there are cases where every tick counts, and while asm is not really supported (that you can use it does not mean it is supported) i do not want to stop anyone from coding in asm.

SBRC requires a register and a bit.
thus the Uart_status must have been a register (.def). And the fe0 was a constant from the dat file.

you need a register to load the register content; LDS will do best. :
LDS R23, USARTC0_STATUS
sbrc r23,4 ; skip if bit 4 is cleared in register r23