Connect all the power and ground pins to insure proper operation. Sometimes
the oscillator will not start and run reliably and you need to adjust the
caps slightly for reliable startup and oscillation. Also check the type of
crystal you are using. You may be overdriving it and need a resistor to the
crystal.


At 01:10 PM 6/9/99 +1000, you wrote:
>Hi...
>
>I'm testing a project that uses a 16C74A. I've used the 16F84 quite a bit
>but this is my first try using the 16C74 with a HS osc at 16Mhz.
>
>Problem:
>I cant even get an led to flash. I know the code is correct. I set the osc
>to HS.
>
>Question:
>Are the two VDD and VSS pins connected internally???
>I got 12ohms between the 2 Vss pins but several Mohms between the Vdd pins.
>Is this correct??
>Should I connect these pins externally???
>Is there something else that could be causing the problem?
>
>Any help would be much appreciated. (the frustration's building)
>
>Thanks,
>Stewart Pye
>
>
Larry G. Nelson Sr.
mailto:L.Nelson@ieee.org
http://www.ultranet.com/~nr