9.1.2 Registers Access Permissions

For PIC32CM GC devices, there is no notion of secure vs non-secure: all peripherals are accessible. The rest of this chapter is dedicated to PIC32CM SG devices.

For PIC32CM SG devices, peripherals are defined as secure or non-secure by the user through the BOOTCFG1/1A H2PB fuses, which are copied by the ROM code in the related registers, or by directly writing in the H2PB registers. The PORT and EIC, when defined as secure in H2PB will behave as Mix-Secure peripherals (See below). The HSM-Lite is always Secure. An empty or invalid BOOTCFG1/1A configuration will be replaced by a hardcoded configuration applied by the ROM code.

Each Peripheral has different register access permissions depending on its Security Attribution :

For peripherals configured as Secure:

• Non-Secure access is discarded and a synchronous bus error is generated
• Secure access is granted

For peripherals configured as Non-Secure:

• Secure and Non-Secure accesses are granted

For Mix-Secure peripherals (PORT and EIC):

• If the peripheral is configured as Non-Secure:
  • Secure access and Non-Secure access are granted
• If the peripheral is configured as Secure in the H2PB registers:
  • Refer to the POR and EIC chapters for details