Starting to develop an example TBSA-M system
Figure 5: Example TBSA-M system using TrustZone for Armv8-M from the PSA Trusted Base System Architecture for M (TBSA-M) document is an abstract depiction of a single core system that uses TrustZone for Armv8-M. The following diagram is a re-creation of Figure 5 from the document with the boxes filled out with real IP:
The timers and power control that are required for the SoC have been added. They are the only peripherals that the system currently has.
In What pieces of IP do I need to make a secure IoT device?, we decided to use a Cortex-M23 processor, AMBA components, and a CryptoCell-312 for our example design of a coffee maker. Now we will focus on the individual AMBA components, timers, and power components. The following subsections explore the rationale behind the IP choices and their placement in the overall layout.