Re-programming 12F509 with ICD2

[PCram]

I'm using 12F509 in my design, and am able to program it using Microchip's ICD2 tool. Once programmed however, I can't seem to clear the memory or reprogram it.

This is a 3v design.

Thanks for any help you can give.

[FvM]

You should read the specification in detail. Many devices need 4.5V minimum for erase/write. Devices, that can be programmed at 3V need higher voltage to remove protection by a chip erase.

[PCram]

That was it. Bumped up to 4.5v and we're reprogramming just as expected.

Thanks very much.