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Having a problem with the EEPROM on PIC32MK1024MCF064

R-K-8592

New Member
Hey folks,

I'm having a problem where after multiple writes into the EEPROM I'm only able to read back the last value that was written.

Look at the difference between a read immediately after a write vs multiple writes and multiple reads. It's as if the value of EEDATA is only updated on a write.

Notes:-

  • Strangely, Reads only work when I DON'T set 'EECONbits.CMD = 0b000' otherwise I get non-printable characters, this happened whether I worked in 32bit or 8bit data
  • I get the same result whether I use the DEVEE0->DEVEE3 initialisation routine or not
  • CFGCON2bits.EEWS = 0 as I'm using a low clock speed, setting this to '1' did not matter
  • Got the same results whether I used 'char' or 'uint32_t' as the type on the EEPROM routines
  • I included a read-back test inside the EEPROM write function that would cause the execution to stay in a loop if there was a mismatch in the written vs read value and it's not locking up, implying that the written value matches the read value.
  • Strange again.. If I include 'EECONbits.CMD = 0b000' in the WRITE function's read-back test, the data being read & printed from the READ function is affected and becomes a non-printable character.
  • Physical external clock speed 8MHz... had no issue with any other peripheral.
Thanks in advance for any assistance.

*******************************************************************************

RESULTS:-

Test set A:-

Step1. Write to EEPROM @ 0xA0 with value 'A'

Step2. Write to EEPROM @ 0xB0 with value 'B'

Step3. Write to EEPROM @ 0xC0 with value 'C'

Step4. Write to EEPROM @ 0xD0 with value 'D'

Step5. Read EEPROM @ 0xA0 and write in USART => value printed:- 'D'

Step6. Read EEPROM @ 0xB0 and write in USART => value printed:- 'D'

Step7. Read EEPROM @ 0xC0 and write in USART => value printed:- 'D'

Step8. Read EEPROM @ 0xD0 and write in USART => value printed:- 'D'

test set B:-

Step1. Write to EEPROM @ 0xA0 with value 'A'

Step2. Read EEPROM @ 0xA0 and write in USART => value printed:- 'A'

Step3. Write to EEPROM @ 0xB0 with value 'B'

Step4. Read EEPROM @ 0xB0 and write in USART => value printed:- 'B'

Step5. Write to EEPROM @ 0xC0 with value 'C'

Step6. Read EEPROM @ 0xC0 and write in USART => value printed:- 'C'

Step7. Write to EEPROM @ 0xD0 with value 'D'

Step8. Read EEPROM @ 0xD0 and write in USART => value printed:- 'D'

*******************************************************************************

The results are the same as Pommie in this thread but I already had the delays etc in my code without success.

My code attached (N.B. I did not set 'EECONbits.CMD = 0b001' and 'EECONbits.CMD = 0b000' in the example code as when I do there isn't any actual data being read whether I cater for 32bit or 8bit data).

Thanks in advance.
 

Attachments

  • EEPROM CODE.txt
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