5.5.1 Activating Flash OTP by ISCP Write Inhibit

ICSP Write Inhibit is activated by executing a pair of NVMCON double-word programming commands to save two 16-bit activation values in the configuration memory space. The target NVM addresses and values required for activation are shown in Table   1. Once both addresses contain their activation values, ICSP Write Inhibit will take permanent effect on the next device Reset.

Only the lower 16 data bits stored at the activation addresses are evaluated; the upper eight bits and second 24-bit word written by the double-word programming should be written as ‘0’s. The addresses can be programmed in any order and also during separate ICSP/Enhanced ICSP/RTSP sessions, but any attempt to program an incorrect 16-bit value or use a row programming operation to program the values will be aborted without altering the existing data.