Config Memory

Purpose

Manage access to the External Electrically Erasable Programmable Memory.

Description

The FEB 64 board contains a 64K (8192 x 8) external memory, which one quarter of this memory is defined as a protected area. The standard FEB64 firmware doesn't contain any code for Write access to the protected memory ensuring a safe storage method for the main parameter i.e: Serial Number (S/N). To simplify the handling of this eepage, a unique structure maps all the necessary parameters following the S/N located as first element of the structure. The size of the structure can therefore not be larger then a quarter of the total memory providing a maximum of 3 R/W [0..2] accessible pages.

Note Protected page is accessible in ReadOnly at page [3].

The current structure is:

// EEPROM structure
struct EEPAGE {
unsigned long SerialN;
unsigned int structsze;
unsigned int rasum[8];
unsigned int rqpump;
unsigned int SWbias;
unsigned int calQpump;
unsigned char rbias [64];
//
// back door access starts @ 92 ->offset=23 (0x17)
float lVIlimit[8]; // vQ iQ +6Vd +6Va -6Va -6Ia +6Ia +6Id
float uVIlimit[8];
float luCTlimit, uuCTlimit;
float lSSTlimit, uSSTlimit;
float lVQlimit,  uVQlimit;
float lIQlimit,  uIQlimit;
float lVBiaslimit, uVBiaslimit;
float lIBiaslimit, uIBiaslimit;
float ext1offset[4];
float ext2offset[4];
float iBiasOffset[8];
float vBiasOffset[8];
};

The Write operation requires extra time. The completion of the Write operation is confirmed when and only when the control bit is turned off, status will reflect operation completion as well.

MSCB Registers

MSCB(1): Error     16bit U               0 (0x0000)        (RO)
EEPROM  R/W error                           0x0800
MSCB(2): Control    8bit U               0 (0x00/00000000) (WO)
Save current setting to EEPAGEx                      0x10
Restore EEPAGEx to memory                            0x20
MSCB(3): Status     8bit U               3 (0x03/00000011) (RO)
EEPAGEx save operation complete                      0x10
EEPAGEx restore operation complete                   0x20
MSCB(4): EEPage     8bit U               0 (0x00/00000000) (WO)
EEPAGE number                                       [0..3]

Operation

The following steps will be used to store data into the page 2 of the external EEPROM.

  1. w 4 2 // Set EEpage 2 for operation.
  2. w 2 0x10 // Initiate Save command
  3. Wait for control bit turned off and status turned on.

DataSheet

EEPROM AT2508A


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