Freescale Semiconductor, Inc.
EEPROM-1
Functional Description
The EEPROM non-volatile register (EENVR1) contains configurations
concerning block protection and redundancy. EENVR1 is physically
located on the bottom of the EEPROM array. The contents are
non-volatile and are not modified by reset. On reset, this special register
loads the EEPROM configuration into a corresponding volatile EEPROM
array configuration register (EEACR1). Thereafter, all reads to the
EENVR1 will reload EEACR1.
The EEPROM configuration can be changed by programming/erasing
the EENVR1 like a normal EEPROM byte. The new array configuration
will take affect with a system reset or a read of the EENVR1.
6.4.5 MCU Configuration
The EEPROM non-volatile 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
non-volatile 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. Note that it is the user’s
responsibility to program the EENVR1 register to the correct system
requirements and verify it prior to use. The new array configuration will
take effect after a system reset or a read of the EENVR1.
6.4.6 EEPROM Protection
The MC68HC908AS60 has a special protection option which prevents
program/erase access to memory locations $08F0–$08FF. This protect
function is enabled by programming the EEPRTCT bit in the EENVR
to 0.
MC68HC908AS60 — Rev. 1.0
Technical Data
EEPROM-1
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