MC68HC711E20CFS2 MOTOROLA [Motorola, Inc], MC68HC711E20CFS2 Datasheet - Page 61

• Manufacturer Part Number: MC68HC711E20CFS2
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

2.5.1.5 EEPROM Byte Erase
2.5.1.6 CONFIG Register Programming
2.5.2 EEPROM Security
M68HC11E Family — Rev. 5
MOTOROLA
NOTE:
This is an example of how to erase a single byte of EEPROM.
Because the CONFIG register is implemented with EEPROM cells, use EEPROM
procedures to erase and program this register. The procedure for programming is
the same as for programming a byte in the EEPROM array, except that the
CONFIG register address is used. CONFIG can be programmed or erased
(including byte erase) while the MCU is operating in any mode, provided that
PTCON in BPROT is clear.
To change the value in the CONFIG register, complete this procedure.
Do not initiate a reset until the procedure is complete.
The optional security feature, available only on ROM-based MCUs, protects the
EEPROM and RAM contents from unauthorized access. A program, or a key
portion of a program, can be protected against unauthorized duplication. To
accomplish this, the protection mechanism restricts operation of protected devices
to the single-chip modes. This prevents the memory locations from being
monitored externally because single-chip modes do not allow visibility of the
internal address and data buses. Resident programs, however, have unlimited
access to the internal EEPROM and RAM and can read, write, or transfer the
contents of these memories.
An enhanced security feature which protects EPROM contents, RAM, and
EEPROM from unauthorized accesses is available in MC68S711E9. Refer to
Section 11. Ordering Information and Mechanical Specifications
part number.
1. Erase the CONFIG register.
2. Program the new value to the CONFIG address.
3. Initiate reset.
BYTEE
Freescale Semiconductor, Inc.
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Operating Modes and On-Chip Memory
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#$16
$103B
0,X
#$17
$103B
DLY10
$103B
BYTE = 1, ERASE = 1, EELAT = 1
Set to BYTE erase mode
Write any data to address to be erased
BYTE = 1, ERASE = 1, EELAT = 1,
EPGM = 1
Turn on high voltage
Delay 10 ms
Turn off high voltage and set
to READ mode
Operating Modes and On-Chip Memory
for the exact
Data Sheet
EEPROM
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