GPIO.3 RESET

[Charlie]

Hi Andrew,

I get what you are saying about the Master clear,but I have Programmed the 675 Quite a few times say 20 and only had problems 5 of those times with the Master clear disabled.So Its hard to say.Once I get the error I erase the Pic wit the Pickit1 and I am back the programming.I don't use the 675 to much so its not a big deal to me.

[Storic]

Opps, when i said their was no varience on the reset on the PICSTART Plus, Their is 13.05VDC on this reset line compaired to the PickFlash reset lind of 12.5VDC,

As extracted from a microchip pdf file "Reset.pdf"

In addition to the reset function, MCLR can also be used to place the device in
programming mode with a VPP voltage, usually 13V, on the pin. Because the MCLR
pin needs to be driven to a high voltage, there is no upper protection diode on this
pin, although there is a voltage clamp circuit for protection.
The MCLR pin has no internal pull-up and must not be left unconnected.

Should this be at 13vdc?

Andrew

[Storic]

OK,
You win for now, I will use my PICSTART Plus and MPLAB to reset the 12F675 micro as required, (its a bit like going backwards)

I raised the clamp zener by another diode to clamp at 13.8v then when the voltage is switched in, a .7v drop is acheived across the another diode and transistor to give me 13.1V. I still get the same result.

Andrew