SPRUHM8K December 2013 – May 2024 TMS320F28374D , TMS320F28375D , TMS320F28376D , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28378D , TMS320F28379D , TMS320F28379D-Q1
On this device, OTP memory, as well as normal Flash, are secure resources. Each zone has a dedicated OTP memory, whereas normal Flash sectors can be allocated to any zone based on the value programmed in the GRABSECT location in OTP memory. Each zone has CSM passwords; read and write accesses are not allowed to resources owned by Z1 from code running from memory allocated to Z2 and conversely. Before programming any secure Flash sector, the user must either unlock the zone to which that particular sector belongs, using PMF or execute the Flash programming code from secure memory that belongs to the same zone. The same is the case for erasing any secure Flash sector. To program the security settings in OTP Flash, the user must unlock the CSM of the respective zone. Unless the zone is unlocked, security settings in OTP Flash cannot be updated. The OTP Flash content cannot be erased.
This device has only one Flash pump used for erase/program operation of normal Flash and OTP Flash. A semaphore mechanism is provided to avoid the conflict between Zone1 and Zone2. A zone needs to grab this semaphore to successfully complete the erase/program operation on the Flash sectors allocated to that zone. A semaphore can be grabbed by a zone by writing the appropriate value in the SEM field of the FLSEM register. For further details of this field, see the register description.