The user has the ability to configure
all LINKs, STACKs and ZONEs that are owned by the user. However, certain system
resources have protections that are fixed in hardware and cannot be altered:
- LINK0 belongs to STACK0, and
STACK0 belongs to ZONE0. These are TI internal resources and cannot be accessed
by user code. User code cannot assign any user LINKs to STACK0, or user STACKs
to ZONE0.
- LINK1 for each CPU always belongs
to STACK1.
- STACK1 for each CPU always
belongs to ZONE1.
- LINK2 for each CPU always belongs
to STACK2.
- STACK2 for each CPU always
belongs to ZONE1.
- In SSUMODE3, the Flash SECCFG
sector can only be read by:
- The SECCFG update owner
defined in SECCFG_UPDATE_CFG, or
- The HSM, if present and
enabled.
- Code instruction fetches to M0
memory always generate a fault.
- Data reads of M0 RAM are allowed
for all CPUs and all LINKs.
- Data writes to M0 RAM are only
allowed for CPU1.LINK2.
- Certain memory and peripheral regions are restricted to one
or more of the special-purpose LINKs (LINK0, LINK1 and LINK2). For details on
these non-APR-based memory protections, refer to the memory-map in the device
data sheet.