Enoch H. Wexler <[EMAIL PROTECTED]> wrote: > Hi Paulo, > > > Strange, the problem does not show in my simplified test... but here's > some real code excerpt and its disassembly (compiled with -Os using > avr-gcc 4.1.0): > > (1) Using TCNT3 directly: > > when = TCNT3 + (7200 / 9 * 10 - 1); /* > 1 sec delay */ > while (when - TCNT3 >= 0) > UDR1; > > 000013ce <kuku>: > 13ce: 80 91 88 00 lds r24, 0x0088 > 13d2: 90 91 89 00 lds r25, 0x0089 > 13d6: 80 91 88 00 lds r24, 0x0088 > 13da: 90 91 89 00 lds r25, 0x0089 > 13de: 83 b1 in r24, 0x03 ; 3 > 13e0: fa cf rjmp .-12 ; 0x13d6 <kuku+0x8> >
The type of TCNT3 is unsigned, so the expression (when - TCNT3 >= 0) is always true due to C type conversion rules. You should cast TCNT3 to int16_t. galen _______________________________________________ AVR-libc-dev mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avr-libc-dev
