MC68HC908AZ32ACFU MOTOROLA [Motorola, Inc], MC68HC908AZ32ACFU Datasheet - Page 81

• Manufacturer Part Number: MC68HC908AZ32ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Program/Erase
Using AUTO Bit
68HC908AZ32A — Rev 0.0
MOTOROLA
Original state of byte (erased)
First event is recorded by programming bit position 0
Second event is recorded by programming bit position 1
Third event is recorded by programming bit position 2
Fourth event is recorded by programming bit position 3
Events five through eight are recorded in a similar fashion
The erase operation changes an EEPROM bit from logic 0 to logic 1. In
a single erase operation, the minimum EEPROM erase size is one byte;
the maximum is the entire EEPROM array.
The EEPROM can be programmed such that one or multiple bits are
programmed (written to a logic 0) at a time. However, the user may never
program the same bit location more than once before erasing the entire
byte. In other words, the user is not allowed to program a logic 0 to a bit
that is already programmed (bit state is already logic 0).
For some applications it might be advantageous to track more than 10K
events with a single byte of EEPROM by programming one bit at a time.
For that purpose, a special selective bit programming technique is
available. An example of this technique is illustrated in
Note that none of the bit locations are actually programmed more than
once although the byte was programmed eight times.
When this technique is utilized, a program/erase cycle is defined as
multiple program sequences (up to eight) to a unique location followed
by a single erase operation.
An additional feature available for EEPROM program and erase
operations is the AUTO mode. When enabled, AUTO mode will activate
an internal timer that will automatically terminate the program/erase
cycle and clear the EEPGM bit. Please see
page 82,
Register
Table 5-2. Example Selective Bit Programming Description
Freescale Semiconductor, Inc.
For More Information On This Product,
EEPROM Erasing
on page 85 for more information.
Go to: www.freescale.com
Description
EEPROM
on page 83 and
EEPROM Programming
EEPROM Control
Program Data
1111:1110
1111:1101
1111:1011
1111:0111
in Binary
n/a
Functional Description
Advance Information
Table
5-2.
1111:0000
1111:1100
1111:1000
in Binary
1111:1111
1111:1110
Result
EEPROM
on
81