XC908AS60ACFU Motorola Semiconductor Products, XC908AS60ACFU Datasheet - Page 113

• Manufacturer Part Number: XC908AS60ACFU
• Description: MC68HC908AZ60A, MC68HC908AS60A Hcmos Microcontroller Unit Technical Data
• Manufacturer: Motorola Semiconductor Products

7.5.3 EEPROM-2 Program/Erase Protection
MC68HC908AZ60A — Rev 2.0
MOTOROLA
NOTE:
As the CGMXCLK or bus clock is user selected, the EEPROM-2
Timebase Divider Register must be configured with the appropriate
value to obtain the 35 µs. The timebase divider value is calculated by
using the following formula:
This value is written to the EEPROM-2 Timebase Divider Register
(EE2DIVH and EE2DIVL) or programmed into the EEPROM-2
Timebase Divider Non-Volatile Register prior to any EEPROM program
or erase operations(see
EEPROM-2 Timebase Requirements
The EEPROM has a special feature that designates the 16 bytes of
addresses from $06F0 to $06FF to be permanently secured. This
program/erase protect option is enabled by programming the EEPRTCT
bit in the EEPROM-2 Non-Volatile Register (EE2NVR) to a logic zero.
Once the EEPRTCT bit is programmed to 0 for the first time:
Once armed, the protect option is permanently enabled. As a
consequence, all functions in the EE2NVR will remain in the state they
were in immediately before the security was enabled.
EE2DIV= INT[Reference Frequency(Hz) x 35 x10
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Programming and erasing of secured locations $06F0 to $06FF is
permanently disabled.
Secured locations $06F0 to $06FF can be read as normal.
Programming and erasing of EE2NVR is permanently disabled.
Bulk and Block Erase operations are disabled for the unprotected
locations $0600-$06EF, $0700-$07FF.
Single byte program and erase operations are still available for
locations $0600-$06EF and $0700-$07FF for all bytes that are not
protected by the EEPROM-2 Block Protect EEBPx bits (see
EEPROM-2 Block Protection
Array Configuration Register
EEPROM-2 Memory
EEPROM-2 Configuration
on page 114 and
on page 121)
on page 112).
-6
Functional Description
on page 112 and
EEPROM-2 Memory
+0.5]
EEPROM-2
Technical Data
113