3.3.1 Control Override Register

This register provides a fail-safe override for some CCI-500 functions. Use this register to resolve problems that you cannot work around in another way.

Usage constraints
If you have to write to this register, you must do so before issuing any shareable transactions or DVM messages to the CCI-500. For example, you can do it very early in the boot sequence before installing any Secure OS.
You can access this register using Secure transactions only, irrespective of the programming of the 3.3.2 Secure Access Register.
Configurations
Available in all CCI-500 configurations.
Attributes
See Table 1.
The following figure shows the bit assignments.
Figure 3-1 ctrl_ovr register bit assignments
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The following table shows the bit assignments.

Table 3-2 ctrl_ovr register bit assignments

Bits Name Function
[31:4] Reserved
-
[3] disable_clock_gating
Disable regional clock gating:
0Regional clock gating operates in the CCI-500. See 1.7 Test features and 2.3 Clocking and reset.
1Disable regional clock gating in the CCI-500.
[2] disable_snoop_filter
Disable the snoop filter:
0Snoop filter operation is defined by the power state input, PSTATE.
1Disable snoop filter operation.
[1] dvm_message_disable
DVM message disable:
0Send DVM messages according to the Snoop Control Registers. See 3.3.8 Snoop Control Registers.
1Disable propagation of all DVM messages.
[0] snoop_disable
Snoop disable:
0
Send snoop requests according to the Snoop Control Registers. See 3.3.8 Snoop Control Registers.
1
Disable all snoops but not DVM messages.
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