SPRUIY2 November 2024 F29H850TU , F29H859TU-Q1
The Safety and Security approach is based on the concept of task isolation. For this section, the example of two distinct tasks (a control task and a communication task) is used. Tasks are unable to view or corrupt the unique program memory, data memory, software stack, and peripheral access of other tasks. From a debugging perspective, each secure zone (ZONE1, ZONE2) has a security password which can only be accessed by enabling the zone for debug with a matching password. Each task has an associated secure Stack Pointer (SECSP2, SECSP3) that is copied into the CPU stack pointer SP = A15 when entering the respective task. When exiting the task, the current contents of the CPU stack pointer is copied into the respective Stack Pointer (SECSP2, SECSP3).
The C29x CPU utilizes the concept of a LINK to tie execution code to a specific task. For example, LINK2 is associated with SECSP2 and ZONE1. Similarly, LINK3 is associated with SECSP3 and ZONE2 as shown in Figure 6-2.