Antonio Sestito

MC9S12XA256CAL - Using the 4k EEPROM

Discussion created by Antonio Sestito on Jun 3, 2009
Latest reply on Jun 4, 2009 by Antonio Sestito

Hi-

 

I ported from a MC9S12A256CPVE to MC9S12XA256CAL Freescale processor. I am having trouble with accessing the 4k EEPROM space. I realize the EEPROM operation is different for both processors.

 

The NVRAM (EEPROM) drivers for the MC9S12A256CPVE are based on AN2400. I am using these same drivers on the MC9S12XA256CAL. They work for EEPROM addresses 0x0800 to 0x0FF0. I am not sure about the other 2k of EEPROM.

 

To verify that my old code was working ok on the new processor, I configured an S19 File write in two 2032-byte NVRAM images at physical locations 0x13F000 (base address 0x????) and 0x13F800 (base address 0x0800). These are byte addressable. The maps are identical.

 

I am able to read locations 0x0800-0x0FF0 and verify against a hardcoded map to make sure the stored contents match what I expect to be there.  

 

For the second map, I am unsure as to where it lives and if I have to manipulate the EPAGE register to access the other 2k?

 

The PRM file is as follows:

 

  EEPROM    = READ_WRITE  DATA_NEAR IBCC_NEAR  0x0C00 TO   0x0FFB;

 

  EEPROM_FC = READ_WRITE  DATA_FAR IBCC_FAR  0xFC0800 TO 0xFC0BFF;
  EEPROM_FD = READ_WRITE  DATA_FAR IBCC_FAR  0xFD0800 TO 0xFD0BFF;
  EEPROM_FE = READ_WRITE  DATA_FAR IBCC_FAR  0xFE0800 TO 0xFE0BFF;

//EEPROM_FF = READ_WRITE  DATA_FAR IBCC_FAR  0xFF0800 TO 0xFF0BFF;

 

Is there a good App Note that will help clear up this confusion or is there a sample project that shows how to use the 4k EEPROM?

 

Any assistance is greatly appreciated.

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