SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The values of L3_MAIN firewall registers on reset are tied in hardware or exported from the control module registers.
Values exported from the control module are intended to give defined rights to the firewalls at reset and thus ensure the content after going out of reset.
The L3_MAIN firewall registers are located in the CORE AON power domain and thus no retention capability is needed. The control module registers are reset by a cold reset only, whereas the L3_MAIN firewall registers are reset by clearing the REGUPDATE_CONTROL[1] FW_LOAD_REQ bit. When the REGUPDATE_CONTROL[1] FW_LOAD_REQ bit comes back automatically to 1, the exported values are loaded.
Before reprogramming the firewall registers and/or before using the FW_LOAD_REQ mechanism, the request must be asserted by configuring the REGUPDATE_CONTROL[0] BUSY_REQ bit.
To load the exported values at run time:
To reprogram the firewall registers at run time:
While reprogramming the firewall registers at run time it must be taken into account that the REGUPDATE_CONTROL[1] FW_LOAD_REQ bit is written as '0' because a value of '1' reloads the firewall default values.
At reset, exported values from the control module can modify hardware reset values.