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EMULATED DATA EEPROM WITH ST7 HDFLASH MEMORY

LD

FLASH_PTRH, A

; located at address 8000h (sector 2).

LD

A, #$00

LD

FLASH_PTRH, A

LD

A, #$55

; 55h is the new data to be write in emulated data

LD

FLASH_DATA, A

; EEPROM byte located at 8000h address

CALL HDemulE2_ByteProg

; Result: status returned in FLASH_CMD high nibble

; < USER APPLICATION PROGRAM >

; -----------------------------------------------------------------------------

; ROUTINE: HDemulE2_ByteRead

; DESCRIPTION: Emulated data EEPROM byte read driver routine

; BEFORE: FLASH_PTRH:L = pointer corresponding to the start address of the

;

memory table allocated to the emulated data EEPROM

;

byte to read

; AFTER:

A

= current emulated data EEPROM byte value

;

FLASH_PTRH:L = address of the current emulated data EEPROM byte value

; RESSOURCES:

;

Program size:

15 bytes

;

Used RAM area: 2 bytes for PTRH:PTRL.

; -----------------------------------------------------------------------------

.HDemulE2_ByteRead

LD

A,[FLASH_PTRH.w]

; Read emulated data EEPROM table content

CP

A, #$FF

; If the value is FFh check next location

JRNE

HDemulE2_ByteRead_end

; Else A = current value.

INC

FLASH_PTRL

JRNE

HDemulE2_ByteRead

INC

FLASH_PTRH

JRT

HDemulE2_ByteRead

.HDemulE2_ByteRead_end

RET

; -----------------------------------------------------------------------------

; ROUTINE: HDemulE2_ByteProg

; DESCRIPTION: Emulated data EEPROM byte programming driver routine

; BEFORE: FLASH_PTRH:L = pointer corresponding to the start address of the

;

memory table allocated to the emulated data EEPROM

;

byte to update

;

FLASH_DATA = data to be programmmed

; AFTER:

FLASH_CMD

= status result of the programming (see embedded status

;

return code definition of the Embedded Command)

; RESSOURCES:

;

Program size:

24 bytes

;

Used RAM area: same as HDFlash Embedded Command

;

- 16 bytes from 00F0h to 00FFh

;

- 116 byte stack

;

(see dedicated chapter for more details)

; -----------------------------------------------------------------------------

.HDemulE2_ByteProg

CALL

HDemulE2_ByteRead

; To look for the current value address

CP

A, FLASH_DATA

; If the data to be written is the same as

JREQ

HDemulE2_ByteProg_end

; current one, skip programming

TNZ

FLASH_PTRL

; Set the new current value address

JRNE

HDemulE2_ByteProg_next

; => previous current - 1

DEC

FLASH_PTRH

.HDemulE2_ByteProg_next

DEC

FLASH_PTRL

CLR

FLASH_CMD

; Set Embedded Command to "Byte programming"