11.4.2 ICSP Program/Erase Disable (Entire Flash OTP by ICSP™ Write Inhibit)

ICSP Program/Erase Disable (Entire Flash OTP by ICSP Write Inhibit) permanently disables unsecured external chip erase and Flash programming. Entire Flash OTP by ICSP Write Inhibit is enabled with the TPED (FTPED[0]) Configuration bit and takes effect when the UCB write-protect FWPUCB word is also programmed with 0x5B9B12E4 value. Enabling Entire Flash OTP by ICSP Write Inhibit does the following:

• Disables chip erase in all modes
• Disables Flash programming and erase in ICSP Programming mode

Entire Flash OTP by ICSP Write Inhibit is intended to be used with the code-protect to permanently disable external readout or modification of the user program via unsecured programming or debug interfaces. When both code-protect and Entire Flash OTP by ICSP Write Inhibit are enabled, external tools cannot enable debug, access user program, modify Flash or disable code-protect. Programming and erase of the Flash can only be done in Mission mode. Mission mode write permissions are not affected by Entire Flash OTP by ICSP Write Inhibit. IRT firmware may support secure programming when Entire Flash OTP by ICSP Write Inhibit is enabled.