16f716

[mwhatley]

Is anyone using the 16F716 ? I'm having trouble getting one to start up. A new project design uses one of these and it new to me. I have one on my proto board and it will not 'spin up'. Vdd and Vss are correct - MCLR tied high - 4 Mhz xtal w/22 pf caps - all the normal stuff. It will program BUT excatly every other time the programming attempt will end with an error that says "Code Programming Error at 0003". Using MCSP and ME Labs programmer. Here is the test code:

@ device pic16f716, XT_OSC
@ device pic16f716, WDT_OFF
@ device pic16f716, PWRT_ON
@ device pic16f716, BOD_OFF
@ device pic16f716, PROTECT_OFF
@ device pic16f716, VBOR_25

Led var PORTB.3

trisa = %11111111
trisb = %00000000

main:
HIGH Led
pause 100
low led
pause 100
goto main
end

I've tried the other option for the last @ device line (VBOR_40) with no joy.

Am I missing something in the data sheet about this PIC?

[sayzer]

What do you mean by "MCLR tied high" ?

No resistor? did you directly connect it to Vdd?

Also, BOD_OFF and VBOR may be having a conflict associated with your MCLR.
Did you check the data sheet for it?


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[mwhatley]

MCLR tied high through 10K resistor - also tried 4.7K.
Different combinations of the @ device tried.
Been going through the data sheets all morning.

After all that I did figure out how to make the chip work. I'm using ICSP and after the chip is programmed nothing works including the oscillator until the power supply is cycled off and back on. I've worked with a couple of dozen different types of PICs and this is the first time I have encountered this.

[Dave]

mwhatley, Do you have a scope? If so put it on the power supply and see if it is comming up within 100 Ms. If not that may be the problem. Also I would shut off the BOD or set it for the lowest setting. I would also lower the caps around the xtal to about 18 Pf.

Dave Purola,
N8NTA