Chaipi Wijnbergen wrote: > here is another idea. If Crystals are defined as Xppm, then how about > increasing your crystal frequency to, lets say 8MHz, then this will > decreas your error by 8M/32K = 250 (assuming both crystals have the same > tolerance). Uh, no, that's not how it works. PPM stands for parts per million - it's a fraction of the crystal frequency. So the absolute error in Hz increases as the frequency increases, for the same tolerance. Dividing down from a higher frequency does not help. The 32kHz crystal is probably going to be better (certainly in frequency stability) than a higher frequency crystal that is not specifically designed for timekeeping. -- Clyde Smith-Stubbs | HI-TECH Software, | Voice: +61 7 3300 5011 clyde@hitech.com.au | P.O. Box 103, Alderley, | Fax: +61 7 3300 5246 http://www.hitech.com.au | QLD, 4051, AUSTRALIA. | BBS: +61 7 3300 5235 ---------------------------------------------------------------------------- For info on the World's best C cross compilers for embedded systems, point your WWW browser at http://www.hitech.com.au, or email info@hitech.com.au