SLUUDG7 December 2025 MSPM33C321A
The implementation defined attribution unit (IDAU) is defined by TI and is referenced in the CPU section of the MSPM33C3-Series 160MHz Microcontrollers Technical Reference Manual. It is important to know how the IDAU is configured since the IDAU's configuration will be used with the SAU to configure the final security level of a region. For example in the MSPM33C32 devices the IDAU is configured such that when the 8th bit of the address is 1 the memory region is defined as non-secure callable and when it's 0 its only non-secure. For example the address 0x1000.0000 is defined as NSC.
The IDAU and SAU are both used to determine the final level of security. The highest security level out of the two is set as the final attributed level of security. For an example of this on the MSPM33C321A see Figure 2-1.