At 03:30 PM 3/24/00 +0000, Cor Grooff wrote: >But is it possible to run the pwm counters at full speed with so few >macrocells? My experience with altera is that a 6-bit counter is about the >widest possible (for a clock of around 40Mhz). Cascading counters is >relatively >expensive (but not prohibitively so - 16bit counters at the full clock >rate are >possible. They just eat up more resources.) > >Scott Most of the simpler Altera parts can go as wide as you want up to the limit of the Logic Array Block. The macrocells include an XOR term which allows very easy implementation of toggle FFs. I'm speaking of the EPM70xx series here (I just LOVE the epm7032slc & epm7128slc parts). With a TFF, only a single product term is required no matter how wide the counter is. Note: you do incur extra propagation delays if you have to span multiple LABs. Earlier versions (ep320, ep600, ep900) were definitely limited as to how wide one could make a counter chain that would clock at maximum clock speed. dwayne Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 16 years of Engineering Innovation (1984 - 2000) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email.