MC68HC08AZ60A Datasheet, PDF (63/480 Pages) Motorola, Inc – Microcontrollers

EEPROM-1
Functional Description
As the CGMXCLK or bus clock is user selected, the EEPROM-1
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:
EE1DIV= INT[Reference Frequency(Hz) x 35 x10^-6 +0.5]
This value is written to the EEPROM-1 Timebase Divider Register
(EE1DIVH and EE1DIVL) or programmed into the EEPROM-1
Timebase Divider Non-Volatile Register prior to any EEPROM-1
program or erase operations(see EEPROM-1 Configuration on page
62 and EEPROM-1 Timebase Requirements on page 62).
5.5.3 EEPROM-1 Program/Erase Protection
The EEPROM-1 has a special feature that designates the 16 bytes of
addresses from $08F0 to $08FF to be permanently secured. This
program/erase protect option is enabled by programming the EEPRTCT
bit in the EEPROM-1 Non-Volatile Register (EE1NVR) to a logic zero.
Once the EEPRTCT bit is programmed to 0 for the first time:
• Programming and erasing of secured locations $08F0 to $08FF is
permanently disabled.
• Secured locations $08F0 to $08FF can be read as normal.
• Programming and erasing of EE1NVR is permanently disabled.
• Bulk and Block Erase operations are disabled for the unprotected
locations $0800-$08EF, $0900-$09FF.
• Single byte program and erase operations are still available for
locations $0800-$08EF and $0900-$09FF for all bytes that are not
protected by the EEPROM-1 Block Protect EEBPx bits (see
EEPROM-1 Block Protection on page 64 and EEPROM-1 Array
Configuration Register on page 71).
NOTE:
Once armed, the protect option is permanently enabled. As a
consequence, all functions in the EE1NVR will remain in the state they
were in immediately before the security was enabled.
MC68HC08AZ60A — Rev 0.0
MOTOROLA
EEPROM-1
Advance Information
63