mc68hc08az60 Freescale Semiconductor, Inc, mc68hc08az60 Datasheet - Page 47

• Manufacturer Part Number: mc68hc08az60
• Description: M68hc08 Family Of 8-bit Microcontroller Units Mcus
• Manufacturer: Freescale Semiconductor, Inc

MCU
Configuration
MC68HC08AZ60
EEPROM
Protection
7-eeprom-1
MOTOROLA
NOTE:
The EEPROM nonvolatile register (EENVR1) also contains
general-purpose bits which can be used to enable/disable functions
within the MCU which, for safety reasons, need to be controlled from
nonvolatile memory. On reset, this special register loads the MCU
configuration into the volatile EEPROM array configuration register
(EEACR1). Thereafter, all reads to the EENVR1 will reload EEACR1.
The MCU configuration can be changed by programming/erasing the
EENVR1 like a normal EEPROM byte. Please note that it is the user’s
responsibility to erase and program the EENVR1 register to the
correct system requirements and verify it prior to use. The new
array configuration will take affect after a system reset or a read of the
EENVR1.
The MC68HC08AZ60 has a special protection option which prevents
program/erase access to memory locations $08F0 to $08FF. This
protect function is enabled by programming the EEPRTCT bit in the
EENVR to 0.
In addition to the disabling of the program and erase operations on
memory locations $08F0 to $08FF the enabling of the protect option has
the following effects.
Once armed, the protect option is permanently enabled. As a
consequence, all functions in the EENVR will remain in the state they
were in immediately before the security was enabled.
Freescale Semiconductor, Inc.
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For More Information On This Product,
Bulk and block erase modes are disabled.
Programming and erasing of the EENVR is disabled.
Unsecure locations ($0800–$08EF) can be erased using the
single byte erase function as normal.
Secured locations can be read as normal.
Writing to a secure location no longer qualifies as a “valid
EEPROM write” as detailed in (see EEPROM Programming) Note
B and
Go to: www.freescale.com
(see EEPROM Erasing)
EEPROM-1
Note A.
MC68HC08AZ60 — Rev. 1.0
Functional Description
EEPROM-1
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