AVR-Chat

Jay,
 
Sorry, you can't do that in a single instruction, you do indeed need
three as TCCR1A is at an I/O location that is not reachable by SBI and
CBI instructions (only I/O addresses 0-31 are).  Not only that, SBI and
CBI take bit numbers not masks and cannot set or clear multiple bits.
Hence, the code the C compiler generates is the most compact you can
get: three instructions to set a single bit.
 
So to answer your final question: no, you didn't get it right.  ;-)

--
Paul Curtis, Rowley Associates Ltd http://www.rowley.co.uk
<http://www.rowley.co.uk/> 
CrossWorks for MSP430, ARM, and (soon) Atmel AVR processors 

	-----Original Message-----
	From: jay marante [mailto:jaythesis@yahoo.com] 
	Sent: 03 June 2004 13:05
	To: AVR-chat@yahoogroups.com
	Subject: [AVR-Chat] asm in ICCAVR
	
	
	i have this code with ICCAVR: 
	
	TCCR1A |= (1<<COM1A1)|(1<<COM1A0); 
	
	i wanted to replace that code with this assembly code: 
	
	asm("SBI TCCR1A,COM1A1+COM1A0\n"); 
	
	because i found out that the assembly code that the compiler
generate has three sets of instructions. i think that if i replace the C
code with the corresponding assembly code, i might optimize the flash
memory. 
	
	but i get this error when i compile it: 
	
	"absolute expression expected" 
	
	what's wring with my code? did i get it right? 
	thanks for the help.