MCU M4FSS shall be the only processor to enable the timeout gasket function.
The following software sequence shall be followed to enable the target timeout gasket
inserted between cbass_mcu and cbass_central.
- Check whether
LPSC_mcu2main_ISO in mcu_psc is disable state or not. If this LPSC is not in
the disable state, MCU M4FSS configures LPSC_mcu2main to be OFF.
- After LPSC_mcu2main is in
disable state,
- If main domain is
under reset, MCU M4FSS waits until the main domain out of reset
- MCU M4FSS triggers a
software flush to the target timeout gasket
- MCU M4FSS configures mcu_PSC to enable LPSC_mcu2main_ISO. This allows the
transactions from mcu domain can reach main domain.
- MCU M4FSS enables target timeout gasket
The above SW sequence needs to be repeated to enable the target side timeout gasket
inserted from cbass_mcu to cbass_wkup_dm path controlled by LPSC_mcu2DM_ISO
The following software sequence shall be followed by enabling the initiator side
timeout gasket:
- MCU M4FSS check whether
LPSC_main2mcu_ISO is in disable state. If it is not in disable state,
configure mcu_psc to put LPSC_main2mcu in disable state
- Wait until LPSC_main2mcu_ISO
in disable state ( which means no pending transactions from main domain to
mcu domain)
- MCU M4FSS triggers a flush operation in initiator timeout gasket through
mcu_ctrl_mmr
- MCU M4FSS configure/enable initiator timeout gasket by defining proper
timeout period through mcu_ctrl_mmr.
- MCU M4FSS enables LPSC_main2mcu_ISO
The initiator side timeout gasket inserted between Cbass_wkup_dm and cbass_wkup_safe
shall follow the similar steps.