FlexNVM partition code for MK20FX512

[simonhaines]

I am partitioning the FlexNVM module on my MK20FX chip, and am using Processor Expert to help me with the required configuration.

The parametrics for the part says that it has 16K of EEPROM. Assuming I want to use the entire FlexNVM for EEE (EEPROM backup size is 512KB) and split the subsystems 1/2 and 2/2, Processor Expert is advising me that the partition code is 0x07 and the data set size value is 0x30. However the reference manual for the part (document number  K20P144M120SF3RM, Rev. 3 November 2014, table 30-4, p. 743) states that using a DEPART value of 0b0111 is reserved. A data set size value of 0x30 (0b110000) correctly has the EEESIZE value as 16K, but sets the EESPLIT values, which the reference manual (table 30-2, p. 742) says: 'This read-only bitfield is reserved and each bit will always be read as one'.

I want to use these values for my P&E MultiLink to partition the FlexNVM as per this FAQ, but I don't want to damage the EEPROM by partitioning with invalid codes.

Simon.

[kerryzhou · Accepted solution]

Hi Simon,

1: EEPROM data set size and partiton codes

The Valid EEPROM Data Set Size Codes and Valid FlexNVM Partition Codes in the document K20P144M120SF3RM, Rev. 3 is not correct. Our document team already found this problem and will update it.

Please refer to the older document about this part, just link this:

The PE configuration is correct:the partition code is 0x07 and the data set size value is 0x30.

I also attach the older reference manual for your reference.

2. Question about 'This read-only bitfield is reserved and each bit will always be read as one'.

  The bit is read-only, so even you write it, it can't be change, and always be read as one, it is just for bit6, bit7, but EESPLIT and EEESIZE should be write, then the EEPROM data set size is 0X30, EESPLIT(bit4, and bit5) is 0b11, EEESIZE(bit0 to 3) is 0b0000.