>Russell McMahon wrote: > > I have now gone to a 4040 counter with a naughty two diode and resistor "AND > gate" to drive the reset. Resistor from RESET to Vcc. Diodes from Q1 and Q3 > to RESET (Anode ends). When both outputs are high the diodes block, resistor > pulls up reset line and both Q's fall again. The resultant reset pulse is > therefore "just long enough:" to cause reset and has the potential to only > partially reset the IC. As I am using just the first two stages the chances > for erroneous operation MAY be reduced compared to higher divide ratios. This should be reliable. But you can eliminate 1 diode - use the resistor in place of the diode. If you think about it, you wind up with the same logic. The pin with the resistor has to be HI before the reset can occur, the pin with the diode also has to be HI or it is still clamping the reset pin LO. In other words, 1 resistor and 1 diode makes an AND gate. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' 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. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads