The OSLAR is a write-only register that locks the debug registers so that the APB interface returns a slave-generated error response for accesses to locked registers. This is useful for the OS to interrupt the debug session cleanly when it wants to save the state of the debug registers.
Figure 12.14 shows the bit arrangement of the OS Lock Access Register.
Table 12.27 shows how the bit values correspond with the OS Lock Access Register functions.
|OS lock access|
OS lock access. Writing a
Writing the key also resets the Operating System Save and Restore Register (OSSRR) sequence to the beginning.