S32k118:Does the Dflash EMU EEPROM backup area have any page flipping operations?

[ZEROOO]

Hello,

    After configuring flexram as an emu EEPROM, will there be page flipping in the flexnvm area, namely the Dflash? Although this is handled by the hardware's own emuEEPROM management system, I would like to know if page flipping occurs during this process. If it does, how long does the page flipping process take and will it block other programs? This is very important for my current development. Could you please provide an answer?

[danielmartynek]

Hello @ZEROOO,

Yes, the state machine is responsible for moving valid records from one sector to another and erasing sectors that contain only invalid records.

This process is handled in the background.

When a new record is written to the Emulated EEPROM (EEE) via FlexRAM, the Command Complete Interrupt Flag (CCIF) is cleared. This indicates that a flash command is in progress.

Once the CCIF flag is set again, it means that all background operations on the backup flash have completed.

The S32K1xx datasheet provides the maximum execution time for these operations.

Table 35. Flash command timing specifications for S32K14x series.

BR, Daniel

[ZEROOO]

Hello @danielmartynek 

    The information you provided is very useful. However, I'm not sure if the following time parameter includes the page flipping time of the hardware emu eeprom. Although this process is automatically completed, I'm worried that a too long page flipping time might block the program's operation.

Also, if a 32K Dflash is used as an EEPROM backup, it will be divided into several areas for page flipping. What is the size of each area?

[danielmartynek]

1. Let me double check the timing.

2. There are 2KB sectors:

BR, Daniel

[danielmartynek]

Hello @ZEROOO,

Based on the internal discussion, the CCIF flag may read as 0 for up to twice the maximum specified time (in cases involving cleanup operations). This is documented in footnote 4 of the specification.

BR, Daniel

[ZEROOO]

Hi @danielmartynek 

    Your answer has been very helpful to me. I would like to ask if the internal page flipping of flexnvm will block the program. From the icon you provided, the time consumed is at the millisecond level.

[danielmartynek · Accepted solution]

Hi @ZEROOO,

During the operation, the CCIF flag is cleared, and the flash block must not be accessed—so yes, it does block it.

BR, Daniel