I'm having trouble erasing the CC2540 flash. I've just assembled my own CC2540 (256K) pcb using the keyfob layout as reference. I'm using a 3.3V regulator to power the CC2540 chip and also have the 32MHZ and 32KHZ crystals soldered on. The debug header pin assignments are almost exactly the same as the keyfob. The only difference on the header is that I'm using a 3.3V regulator to power the CC2540 chip so pin 9 of the header was left unconnected. I have the header Vsense pin2 of the CC debugger connected to the regulator 3.3V output.
So far I see that the CC debugger green light appear and the CC2540 was recognized by the SmartRF Flash Programmer. I can even read IEEE (primary and secondary). The problem comes up when I try to erase the CC2540, I get an error message:
CC2540 ID1257: - Flash erase failed
In IAR, the download options were not available so I cannot flash the program through there.
I believe my ground is ok since I used a DMM to do a continuity check (pin to gnd) and got 0.6-0.7V for each of the pins. One thing I found was that the decouple pin output was 2V. Could this be a problem? It might be possible that the chip was damaged, but how would the CC debugger still recognize it? Any suggestions or helpful comments would be much appreciated.
