AN2156 Freescale Semiconductor / Motorola, AN2156 Datasheet - Page 75

• Manufacturer Part Number: AN2156
• Description: Programming and Erasing FLASH and EEPROM Memories on the MC68HC908AS60A/AZ60A
• Manufacturer: Freescale Semiconductor / Motorola

EEPROMroutine_End:
***************************************************************************
*****
***************************************************************************
* This routine determines whether EE1CR or EE2CR should be written to and *
* which bit(s) in the EExCR is set or clear based on the accumulator
* value and the EEPROM address specified by EEPROM_addr.
* Initializations required:
*
*
*
* Values returned:
*
***************************************************************************
WriteEECR:
EEPROM2:
EEPROM1:
WriteEECR_End:
AN2156
MOTOROLA
; Delay Evaluation: Point E1
;
;-----------------------------------------------------------------;
; Delay Time tEEFPV Evaluation
;
;-----------------------------------------------------------------;
; Delay Evaluation: Point S2
;
; Delay Evaluation: Point E2
;
- Set bit(s) in accumulator for making bit(s) in the EExCR set or
- Load EEPROM_addr to HX registers
- None
clear
sta
jsr
bset
lda
jsr
Measure low level period on Port D bit 3 pin using a scope
bclr
lda
dbnza *
bset
lda
jsr
lda
sta
sta
cli
rts
cphx
bhs
cphx
bhs
eor
sta
bra
eor
sta
rts
times
ms_delay
3,PTD
#eepgm.
WriteEECR
3,PTD
#$52
3,PTD
#eelat.
WriteEECR
#$00
EE1CR
EE2CR
#EE2DIVHNVR
EEPROM2
#eeprom-1
EEPROM1
EE2CR
EE2CR
WriteEECR_End
EE1CR
EE1CR
Write to EEPROM Control Register
Freescale Semiconductor, Inc.
For More Information On This Product,
; tEEBYTE/tEEBULK/tEEBLOCK/tEEPGM
; (all are 10 ms)
;Set Port D bit 3
;Step 5 - Clear EEPGM bit
;Clear Port D bit 3
;Step 6 - Wait for time tEEFPV (101us)
; 2 + (3 x 82) cycles = 248 cycles
;Set Port D bit 3
;Step 7 - Clear EELAT bit
;Clear all bits in the EExCR
;Enable interrupts
;If address >= $FF70, branch to EEPROM2
;If address >= $0800, write to EEPROM1
;Write to EE2CR register
;Write to EE1CR register
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(Time between points S2 and E2)
Standard EEPROM Assembly Source Code
;
;
*****
*
*
*
*
*
*
*
*
Application Note
75