4.3.5. Lock Register, SYS_LOCK

The SYS_LOCK register at 0x10000020 locks or unlocks access to the oscillator registers, SYS_OSCx.

The control registers cannot be modified while they are locked. This mechanism prevents the registers from being overwritten accidently. The registers are locked by default after a reset. Figure 4.6 shows the bit assignment of the register.

Figure 4.6. Lock Register, SYS_LOCK

Lock Register, SYS_LOCK

Table 4.8 describes the baseboard Lock Register bit assignment.

Table 4.8. Lock Register, SYS_LOCK bit assignment

Bits

Access

Description

[31:17]

Reserved. Use read-modify-write to preserve value.

[16]

Read-only

LOCKED, this bit indicates if the control registers are locked or unlocked:

0 = unlocked

1 = locked.

[15:0]

Read/Write

LOCKVAL, write the value 0xA05F to unlock the control registers. Write any other value to this register to lock the registers.


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