Firmware User Manual (AE-step)
12
Revision 1.02
2019-04-24
TLE984x Firmware User Manual
BootROM Startup procedure
3.5.2
Post User Mode Entry Recommendations
Upon USER MODE entry, it is highly recommended to to perform the following checks and actions:
Prior to any NVM operation, it is recommended to implement a test of SYS_STRTUP_STS.Bit1.
If the bit is clear then the data flash mapping is consistent NVM write/erase operation can be performed. To
see if the Service Algorithm might have been active the user has to check the MEMSTAT register. If the Service
Algorithm was active the user has to expect that expected logical data flash pages are not present anymore.
The user has to take care of this and reconstruct any missing page. Furthermore it might be possible that the
Service Algorithm reports an unrecoverable failure inside the Data Flash, then the same corrective actions
shall be applied as described in the following paragraph for the case that SYS_STRTUP_STS.Bit1 is set.
If the SYS_STRTUP_STS.Bit1 is set, then the data flash mapping is inconsistent, the mapping might not be
complete and any NVM operation like write or erase is not safe and might cause further inconsistencies inside
the data flash. As corrective actions the user might reset the device (cold reset) in order to give the Service
Algorithm a chance to repair the data flash sector. If this attempt fails again, then a sector erase is needed to
reinitialize the data flash sector and to remove any mapping inconsistency. After the data flash sector has
been erased the user has to take care of reconstructing the expected logical data flash pages.
The reset source should get read from the PMU Reset Status Register (PMU_RESET_STS). Clearing
PMU_RESET_STS is strongly recommended in the user startup code, as uncleared bits can cause a wrong reset
source interpretation in the BootROM firmware after the next reset (e.g. handling a warm reset as a cold reset)
The system startup status register SCU.SYS_STRTUP_STS should get checked for any startup fails. The bit
INIT_FAIL which is a logical or of all modul status bits should get checked at least. See the TLE984xQX User’s
Manual for a detailed register description
3.6
Flowcharts for User BSL / Debug Modes
This section provides the firmware flow charts that are relevant for user and debug boot modes.
