Cortex-A8 Technical Reference Manual - ARM Information Center

12.4.18 Operating System Lock Status Register
The OSLSR contains status information about the locked debug registers.
Figure 12-15 shows the bit arrangement of the OSLSR.
Debug
Figure 12-15 OS Lock Status Register format
Table 12-28 shows how the bit values correspond with the OS Lock Status Register functions.
12.4.19 Operating System Save and Restore Register
31 3
Bits Field Function
[31:3] - RAZ.
Reserved
The OSSRR is a 32-bit read/write register that enables an operating system to save (prior to
power-up) or restore (after power-down) those debug registers that reside on the core power
domain while the OS lock is set.
Figure 12-16 shows the bit arrangement of the OSSRR.
32-bit access
Lock bit
Lock implemented bit
Table 12-28 OS Lock Status Register bit functions
[2] 32-bit access Indicates that a 32-bit access is required to write the key to the OS Lock Access
Register. This bit always reads 0.
[1] Lock bit Locked bit:
0 = lock is not set
1 = lock is set.
Writes are ignored. On Present, this bit initializes to the value of
DBGOSLOCKINIT, that is, the OS lock is set if DBGOSLOCKINIT is HIGH.
[0] Lock implemented bit Lock implemented bit. It indicates that the OS lock functionality is implemented. This
bit always reads 1.
31 0
OS save and restore
Figure 12-16 OS Save and Restore Register format
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