A.5.6 Miscellaneous security expansion signals

The following table lists the signals required by the PPCs, MSCs, and ACGs in the system.

Table A-18 Security expansion signals

Signal name Width Direction Description
SECRESPCFG 1 Output

This signal configures how to respond to an access when a security violation occurs.

0 - Read-Zero Write Ignore

1 - bus error

This signal is controlled by the SECRESPCFG register.

ACCWAITna 1 Output

This signal controls any external gating unit that might be required to block accesses to the system from the AHB Slave Expansion interfaces.

1 – No Gating

0 – Access Gated.

This signal is controlled by the BUSWAIT register.

ACCWAITNSTATUS 1 Input

This status signal indicates the state of any external gating unit that can be used to block accesses to the system from the AHB Slave Expansion interfaces.

1 – No Gating

0 – Access Gated.

This signal can be read from the BUSWAIT register.

CERTDISABLEEXT 1 Input

The Certificate Path Disable External input signal allows an external entity to drive this signal HIGH to directly set the CERTDISABLE register bit in the SCSECCTRL register.

Tie to HIGH to disable certificate access by default. Tie to LOW if this signal is not used.

a Use ACCWAITn to control ACGs in the expansion system, in order to block access to the system after a reset, until the security configuration happens. NSMSCEXP resets to all Secure, which means that all masters that use NSMSCEXP for a security configuration will be a Secure master by default.
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