User Manual
313
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
NVM Module (Flash Memory)
the register MEMSTAT to the user application. The user application has to evaluate the
register in order to perform appropriate corrective actions if needed. Furthermore the register
provides status information about the MapRAM Initialization function executed
during start-up. It allows the user directly to jugde the data integrity of the data flash. In case the
register reports a MapRAM Initialization fail it is not recommended to perform any
further write operation to the data flash, as this migh result in unrecoverable loss of data integrity inside the
data flash. A reinitialization of the data flash by performing a SECTOR_ERASE will then be the only solution.
Instead a reset of the device might be triggered in order to execute the Service Algorithm. If even the Service
Algorithm fails to resolve the data integrity issue then the data flash sector has to be reinitialized. In order to
provide full reliability of the data flash module and to avoid any loss of data integrity inside the data flash the
user has to ensure that no NVM operation which changes the content of the data flash module, program or
erase, get interrupted at any time. Appropriate actions to support this could be:
• the capacitor at the VS input has to be dimensioned large enough to provide enough charge to the device
to keep the VS supply in the specified range until the NVM operation ended normally
• check the supply voltage to be high enough and stable before a NVM operation gets started in order to end
the NVM operation normally without interruption
• disable interrupts in the system before a NVM operation gets started, reenable the interrupts upon return
• avoid nested NVM operations
• trigger the WDT1 in short-open-window mode for any NVM operation
• evaluate the return values of the NVM operations and perform corrective actions accordingly
• check the data integrity of the data flash by executing the USER_MAPRAM_INIT function and perform
corrective actions accordingly
Note:
The above mentioned recommendation do also apply to NVM write/erase operations to the code
flash and as well as to the 100TP pages.
12.2.15 Code and Data Access through the AHB-Lite Interface
The system provides access to the data stored in the NVM cell array through an AHB Lite interface. Whenever
the core needs to fetch instructions or read data form or write data into the NVM module, a proper AHB Lite
compliant access request is forwarded by the bus matrix block into the module.