Technical Data
MC68HC11E Family
—
Rev. 4
102
Operating Modes and On-Chip Memory
MOTOROLA
Operating Modes and On-Chip Memory
ERASE
—
Erase Mode Select Bit
0 = Normal read or program mode
1 = Erase mode
EELAT
—
EEPROM Latch Control Bit
0 = EEPROM address and data bus configured for normal reads
and cannot be programmed
1 = EEPROM address and data bus configured for programming or
erasing and cannot be read
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
Table 4-8. EEPROM Erase
BYTE
ROW
Action
0
0
Bulk erase (entire array)
0
1
Row erase (16 bytes)
1
0
Byte erase
1
1
Byte erase