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EMULATED DATA EEPROM WITH ST7 HDFLASH MEMORY

4 ASSEMBLER PROGRAM EXAMPLE

The following program example describes a driver routine to be called to emulate data

EEPROM with a HDFlash ST7 device (data value limited to 00h..FEh). This example assumes

that all restrictions are taken into account.

st7/

;******************************************************************************

; TITLE:

HDdataE2Emul.asm

; AUTHOR:

CMG_MCD Application Team

; DESCRIPTION: Data EEPROM emulation with HDFlash memory (ST72F521 example)

;******************************************************************************

TITLE "HDdataE2Emul.asm"

BYTES

FCSR

EQU

$29 ; HDFLASH Control register definition

FLASH_CMD

EQU

$FF

; Reserved RAM area for HDFLASH Embedded Commands

FLASH_SECT

EQU

$FE

FLASH_PTRL

EQU

$FD

; PTRH:PTRL is also used for read operation

FLASH_PTRH

EQU

$FC

FLASH_ENDL

EQU

$FB

FLASH_ENDH

EQU

$FA

FLASH_DATA

EQU

$F9

FLASH_FREQ

EQU

$F8

#DEFINE

FREQ

8

; Application frequency is 8MHz

WORDS

SEGMENT WORD AT 1000-DFFF 'HDFlash Sect2'

< MEMORY LOCATION OF THE EMULATED DATA EEPROM : FROM 8000h IN THIS EXAMPLE >

SEGMENT WORD AT E000-EFFF 'HDFlash Sect1'

< POTENTIAL MEMORY LOCATION FOR EMULATED DATA EEPROM >

SEGMENT WORD AT F000-FFFF 'HDFlash Sect0'

; < RESET >

LD

A,#$56

; Enter RASS keys to unlock FCR register

LD

FCR,A

LD

A,#$AE

LD

FCR,A

; < USER APPLICATION PROGRAM >

LD

A, #$80

; Read emulated data EEPROM value with a pointer

LD

FLASH_PTRH, A

; located at address 8000h (sector 2).

LD

A, #$00

LD

FLASH_PTRH, A

CALL HDemulE2_ByteRead

; Result: current value in A register

; < USER APPLICATION PROGRAM >

LD

A, #$80

; Read emulated data EEPROM value with a pointer