
Operating Modes and On-Chip Memory
Data Sheet
M68HC11E Family — Rev. 5
60
Operating Modes and On-Chip Memory
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MOTOROLA
EPGM — EPROM/OTPROM/EEPROM Programming Voltage Enable Bit
0 = Programming voltage to EEPROM array switched off 
1 = Programming voltage to EEPROM array switched on 
During EEPROM programming, the ROW and BYTE bits of PPROG are not used. 
If the frequency of the E clock is 1 MHz or less, set the CSEL bit in the OPTION 
register. Recall that 0s must be erased by a separate erase operation before 
programming. The following examples of how to program an EEPROM byte 
assume that the appropriate bits in BPROT are cleared. 
PROG 
LDAB
STAB
STAA
#$02
$103B
$XXXX
EELAT = 1 
Set EELAT bit 
Store data to EEPROM address 
(for valid EEPROM address see memory 
map for each device) 
EELAT = 1, EPGM = 1 
Turn on programming voltage 
Delay 10 ms 
Turn off high voltage and set 
to READ mode 
LDAB
STAB
JSR
CLR
#$03
$103B
DLY10
$103B
2.5.1.3  EEPROM Bulk Erase 
This is an example of how to bulk erase the entire EEPROM. The CONFIG register 
is not affected in this example. 
BULKE
LDAB
STAB
STAA
#$06
$103B
$XXXX
EELAT = 1, ERASE = 1
Set to BULK erase mode
Store data to any EEPROM address (for 
valid EEPROM address see memory map 
for each device) 
EELAT = 1, EPGM = 1, ERASE = 1
Turn on high voltage 
Delay 10 ms 
Turn off high voltage and set 
to READ mode 
LDAB
STAB
JSR
CLR
#$07
$103B
DLY10
$103B
2.5.1.4  EEPROM Row Erase 
This example shows how to perform a fast erase of large sections of EEPROM. 
ROWE
LDAB
STAB
STAB
LDAB
STAB
JSR
CLR
#$0E
$103B
0,X
#$0F
$103B
DLY10
$103B
ROW = 1, ERASE = 1, EELAT = 1 
Set to ROW erase mode 
Write any data to any address in ROW 
ROW = 1, ERASE = 1, EELAT = 1, EPGM = 1 
Turn on high voltage 
Delay 10 ms 
Turn off high voltage and set 
to READ mode 
F
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