Operating Modes and On-Chip Memory
EPROM/OTPROM
M68HC11E Family — Rev. 5
Data Sheet
MOTOROLA
Operating Modes and On-Chip Memory
For More Information On This Product,
Go to: www.freescale.com
53
Using the on-chip EPROM/OTPROM programming feature requires an external
12-volt nominal power supply (V
PPE
). Normal programming is accomplished using
the EPROM/OTPROM programming register (PPROG).
PPROG is the combined EPROM/OTPROM and EEPROM programming register
on all devices with EPROM/OTPROM except the MC68HC711E20. For the
MC68HC711E20, there is a separate register for EPROM/OTPROM programming
called the EPROG register.
As described in the following subsections, these two methods of programming and
verifying EPROM are possible:
1.
Programming an individual EPROM address
2.
Programming the EPROM with downloaded data
2.4.1 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
F
Freescale Semiconductor, Inc.
n
.