Thanks for the comments! Reply comments and more info below... On Fri, 10 Sep 1999 14:11:37 -0500 Barry King writes: >> 1. PIC running on +3V >Is your 16C622 rated for 3V? Not all PICs are. Try temporarily at >5V, then you'll know it that's it. The 16C62X is rated 2.5V to 6.0V. However, bumping the voltage from 3.0 up to 4.5 DOES make the OSC2 pin run. Note that at 2.5V, a triangle wave can be seen on the OSC1 pin, which is what I would expect with this oscillator circuit. My GUESS is that the output of the schmitt in the RC oscillator is not swinging far enough when the power supply is 3V to drive the following dividers. I thought that maybe the pulse width (during capacitor discharge) out of the oscillator was perhaps too short for the divider, so I increased the capacitor size (decreasing frequency, but also increasing the amount of time it takes the FET to discharge the capacitor, increasing the pulse width coming out of the oscillator and driving the dividers). This, however, resulted in no change on OSC2. So, it appears to me that it is indeed a voltage threshold problem between the schmitt oscillator and the divider. I do have Microchip engineers checking into it for me, but I thought I'd do a little "parallel processing" here and seek solutions from everywhere simultaneously. > >> 3. Config word set as below: >> 2007 3FF3 00038 __CONFIG _CP_OFF & _RC_OSC >& >> _PWRTE_ON & _WDT_OFF >Make SURE you've re-compiled correctly for the '622 target. The >bits in the Config word may be different, and the address of the >Config word may be different. Addresses and config contents are the same for the 61 and the 622. > >> 4. Square wave visible on pin 15 (osc out) when using >16c61, but >> pin sits low with 16c622A. > >Which proves the osc is not working right- wrong config burn is the >most likely reason, IMHO. > As discussed above, the fact that there's a triangle on OSC1 indicates to me that the oscillator is RUNNING, but the dividers are not (nothing on OSC2). I'm going to do some more measurements for Microchip on Monday. We'll see what we come up with! Maybe I need to go to a UJT oscillator! Again, thanks for the comments! Harold Harold Hallikainen harold@hallikainen.com Hallikainen & Friends, Inc. See the FCC Rules at http://hallikainen.com/FccRules and comments filed in LPFM proceeding at http://hallikainen.com/lpfm ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: http://dl.www.juno.com/dynoget/tagj.