
Operating Modes and On-Chip Memory
EPROM/OTPROM
MC68HC11E Family
—
Rev. 4
Technical Data
MOTOROLA
Operating Modes and On-Chip Memory
93
As described in the following subsections, these two methods of
programming and verifying EPROM are possible:
Programming an individual EPROM address
Programming the EPROM with downloaded data
4.5.1 Programming an Individual EPROM Address
In this method, the MCU programs its own EPROM by controlling the
PPROG register (EPROG in MC68HC711E20). Use these procedures
to program the EPROM through the MCU with:
The ROMON bit set in the CONFIG register
The 12-volt nominal programming voltage present on the
XIRQ/V
PPE
pin
The IRQ pin must be pulled high.
NOTE:
Any operating mode can be used.
This example applies to all devices with EPROM/OTPROM except for
the MC68HC711E20.
EPROG
LDAB
STAB
#$20
$103B
Set ELAT bit in (EPGM = 0) to enable
EPROM latches.
Store data to EPROM address
STAA
LDAB
STAB
$0,X
#$21
$103B
Set EPGM bit with ELAT = 1 to enable
EPROM programming voltage
Delay 2–4 ms
Turn off programming voltage and set
to READ mode
JSR
CLR
DLYEP
$103B
This example applies only to MC68HC711E20.
EPROG
LDAB
STAB
#$20
$1036
Set ELAT bit (EPGM = 0) to enable
EPROM latches.
Store data to EPROM address
STAA
LDAB
STAB
$0,X
#$21
$1036
Set EPGM bit with ELAT = 1 to enable
EPROM programming voltage
Delay 2–4 ms
Turn off programming voltage and set
to READ mode
JSR
CLR
DLYEP
$1036