[FAQ] TDA4VL-Q1: How to turn off DebugSS for troubleshooting and/or system requirements

Below is a series of Linux commands for register writes as a proof-of-concept, which should be translatable to other OS. User can attempt to connect JTAG to confirm if JTAG is not accessible after the register writes.

#set next state in MDCTL register to Disable for LPSC_DEBUG2DMSC

devmem2 0x42000a08 w 0x80000102

#set PTCMD to GO

devmem2 0x42000120 w 0xFFFFFFFF

#[optional] check state. Least significant hex value should be 0x2

devmem2 0x42000808



#set next state in MDCTL register to Disable for LPSC_main_debug

devmem2 0x00400a34 w 0x80000102

#set psc_PTCMD_j to GO and reflect MDCTL change

devmem2 0x00400120 w 0xFFFFFFFF

#[optional] check state. Least significant hex value should be 0x2

devmem2 0x00400834



#[optional] See if DEBUGSS is active. 0x1 is active, 0x0 is non-active. Expectation is 0x0 after register writes were done

devmem2 0x43014300

For some context, there is no device ID associated with LPSC_DEBUG2DMSC and LPSC_main_debug. Hence reads through the TISCI API (Sciclient_pmGetModuleState) does not actually give the status of the DebugSS as the TISCI API tracks power state associated to device ID.

Regards,

Takuma