MC68HC912DG128 Datasheet, PDF (436/452 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Appendix: MC68HC912DG128A EEPROM
22.5 Program/Erase Operation
A program or erase operation should follow the sequence below if AUTO
bit is clear:
1. Write BYTE, ROW and ERASE to desired value, write EELAT = 1
2. Write a byte or an aligned word to an EEPROM address
3. Write EEPGM = 1
4. Wait for programming, t_PROG or erase, t_ERASE delay time (10ms)
5. Write EEPGM = 0
6. Write EELAT = 0
If AUTO bit is set, steps 4 and 5 can be replaced by a step to poll the
EEPGM bit until is cleared.
It is possible to program/erase more bytes or words without intermediate
EEPROM reads, by jumping from step 5 to step 2.
22.6 Shadow Word Mapping
The shadow word is mapped to location $_FC0 and $_FC1 when the
NOSHW bit in EEMCR register is zero. The value in the shadow word is
loaded to the EEMCR, EEDIVH and EEDIVL after reset. Table 22-4
shows the mapping of each bit from shadow word to the registers
Table 22-4. Shadow word mapping
Shadow word location
Register / Bit
$_FC0 bit 7
EEMCR / NOBDML
$_FC0, bit 6
EEMCR / NOSHW
$_FC0, bit 5
EEMCR / bit 5⁽¹⁾
$_FC0, bit 4
EEMCR / bit 4⁽¹⁾
$_FC0, bit 3:2
not mapped⁽²⁾⁾
$_FC0, bit 1:0
EEDIVH / bit 1:0
$_FC1, bit 7:0
EEMCR / bit 7:0
1. Reserved for testing. Must be set to one in user application.
2. Reserved. Must be set to one in user application for future compatibility.
Technical Data
436
MC68HC912DG128 — Rev 3.0
Appendix: MC68HC912DG128A EEPROM
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