Visible to Intel only — GUID: utw1685984236322
Ixiasoft
Visible to Intel only — GUID: utw1685984236322
Ixiasoft
3.4.3. 2123467: No response to Debug APB access during a core reset, in Direct connect configuration
Description
If there is traffic to a core on the Debug APB bus when the core is powered off, the access should receive a PSLVERR response. If the core reset is applied, then the APB bus will not provide a response, which can lead to a system deadlock.
Conditions
- The core is in the OFF power mode.
- The system is asserting the nCPUPORESET core reset signal LOW.
- The DebugBlock remains powered ON.
- An access is made to the core on the Debug APB bus.
Impact
The PREADYDC and PSLVERRDC signals on the cluster APB interface are incorrectly driven LOW during reset, which means that any access in the interface will not receive a response. This can lead to a system deadlock.
Workaround
If the system and software can ensure that no APB accesses can be made while the core is powered off, then this will avoid this erratum.
If the system can assert the nPRESET signal to the DebugBlock whenever the core is powered off, then this will also avoid this erratum.
Category
Category C