Hi all, Just too share some thoughts. I used to work with the avr's like avr ATtiny861/461/261 and ATmega16. Now i am porting a program to other chips like the ATmega 48P - 328P series and ATmega 164P-644P series.
When i look at the register summary, it really makes me sad. Vast area's of reserved space and precious registers are push beyond the 0x1F or 0x3F boundaries for no obvious reason. Now i understand you cannot squeeze everything into the lowest region. But why so much empty space? The use of sbi/cbi and in/out could be a lotter better. It is not just the number of instructions that goes up needlessly. Also, sbi/cbi makes interrupt immune switching of bits possible. For example, if at least the TIMSK registers had been below 0x1F (makes atomic enable/disable of timerinterrupts possible) or there been a few extra GPIO present below 0x1F. The way this is designed does not honor the efficient way the instructionset was meant to operate imho. I'dd like to hear oppinions and hope someone of the Atmel hardware team cares to react. Regards, Ruud. _______________________________________________ AVR-chat mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avr-chat
