Changing the GPIF Waveform Descriptors for the EZ-USB FX2/FX2LP (CY7C68013 /CY7C68013A) On the Fly

Question: What should I be aware of when changing the GPIF waveform descriptors in the middle of a GPIF transfer?

 

Answer:

GPIF waveform locations should not be changed while the GPIF is in the middle of a transfer. The firmware should first check that the GPIF is IDLE (using "if (GPIFTRIG & 0x80)"). A premature abort (GPIFABORT=0xFF) may also help to ensure that the GPIF is at a ground-zero state.