"Vincent Trouilliez" wrote: > On Wed, 11 Mar 2009 10:33:09 +1030 > "Daniel O'Connor" <[email protected]> wrote: > >> Try the -B option, although for me it doesn't seem to make a big difference >> (although I need -B 10 to program a new part due to the fuse settings). > > Arf... it does make a difference here.. it makes it twice as slow with > a value of 10, makes the communication fail with 0.1, and with 0.15, > ...
The uC's frequency has to be at least 4x the frequency generated by the bit clock. A bit clock of 1 corresponds to 1 micro second, so that gives you 1MHz, and will work with uC's running at 4MHz or faster. To get the fastest bit clock value that should work, divide 4 by the frequency of the uC in MHz. E.g. If the uC is clocked at 16MHz try 0.25 and for 8MHz try 0.5. For a bit clock of 0.1 the uC would need a clock at 40MHz or faster, and for a bit clock of 0.15 it would need a clock at 27MHz (rounded up) or faster. -Preston _______________________________________________ AVR-chat mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avr-chat
