MC68HC11F1 Datasheet, PDF (31/68 Pages) Motorola, Inc – Technical Summary 8-Bit Microcontroller

Bit 1 — Not implemented. Reads always return one and writes have no effect.
EEON — EEPROM Enable
This bit is forced to one in single-chip and bootstrap modes. In test mode, EEON is forced to zero out
of reset. In expanded mode, the EEPROM obeys the state of this bit.
0 = EEPROM is removed from the memory map.
1 = EEPROM is present in the memory map.
Refer to 6.4 CONFIG Register Programming for instructions on programming this register.
6.3 EEPROM Programming and Erasure
Programming and erasing the EEPROM is controlled by the PPROG register, subject to the block pro-
tect (BPROT) register value. To erase the EEPROM, ensure that the proper bits of the BPROT register
are cleared, and then complete the following steps:
1. Write to PPROG with the ERASE and EELAT bits set and the BYTE and ROW bits set or
cleared as appropriate.
2. Write to the appropriate EEPROM address with any data. Row erase ($xE00–$xE0F, $xE10–
$xE1F,... $xFF0–$xFFF) requires a single write to any location in the row. Perform bulk erase
by writing to any location in the array.
3. Write to PPROG with the ERASE, EELAT, and EEPGM bits set and the BYTE and ROW bits
set or cleared as appropriate.
4. Delay for 10 ms (20 ms for low-voltage operation).
5. Clear the EEPGM bit in PPROG to turn off the high voltage.
6. Clear the PPROG register to reconfigure EEPROM address and data buses for normal opera-
tions.
To program the EEPROM, ensure that the proper bits of the BPROT register are cleared, and then com-
plete the following steps:
1. Write to PPROG with the EELAT bit set.
2. Write data to the desired address.
3. Write to PPROG with the EELAT and EEPGM bits set.
4. Delay for 10 ms (20 ms for low-voltage operation).
5. Clear the EEPGM bit in PPROG to turn off the high voltage.
6. Clear the PPROG register to reconfigure EEPROM address and data buses for normal opera-
tions.
6.3.1 Programming a Byte
The following example shows how to program an EEPROM byte. This example assumes that the ap-
propriate bits in BPROT are cleared and that the data to be programmed is present in accumulator A.
PROG
LDAB
STAB
STAA
LDAB
STAB
JSR
CLR
#$02
$103B
$FE00
#$03
$103B
DLY10
$103B
EELAT=1, EEPGM=0
Set EELAT bit
Store data to EEPROM address
EELAT=1, EEPGM=1
Turn on programming voltage
Delay 10 ms
Turn off high voltage and set to READ mode
6.3.2 Bulk Erase
The following example shows how to bulk erase the 512-byte EEPROM. The CONFIG register is not
affected in this example. Note that when the CONFIG register is bulk erased, CONFIG and the 512-byte
array are all erased.
BULKE
LDAB
STAB
#$06
$103B
ERASE=1, EELAT=1, EEPGM=0
Set EELAT bit
MC68HC11F1/FC0
MC68HC11FTS/D
MOTOROLA
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