MC68HC908AZ32ACFU MOTOROLA [Motorola, Inc], MC68HC908AZ32ACFU Datasheet - Page 82

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

EEPROM
EEPROM
Programming
Advance Information
82
NOTE:
NOTE:
The unprogrammed or erase state of an EEPROM bit is a logic 1.
Programming changes the state to a logic 0. Only EEPROM bytes in the
non-protected blocks and the EENVR register can be programmed.
Use the following procedure to program a byte of EEPROM:
If using the AUTO mode, also set the AUTO bit during Step 1.
A. EERAS1 and EERAS0 must be cleared for programming. Setting the
EELAT bit configures the address and data buses to latch data for
programming the array. Only data with a valid EEPROM address will be
latched. If EELAT is set, other writes to the EECR will be allowed after a
valid EEPROM write.
B. If more than one valid EEPROM write occurs, the last address and
data will be latched overriding the previous address and data. Once data
is written to the desired address, do not read EEPROM locations other
than the written location. (Reading an EEPROM location returns the
latched data and causes the read address to be latched).
C. The EEPGM bit cannot be set if the EELAT bit is cleared or a non-
valid EEPROM address is latched. This is to ensure proper
programming sequence. Once EEPGM is set, do not read any EEPROM
locations; otherwise, the current program cycle will be unsuccessful.
When EEPGM is set, the on-board programming sequence will be
activated.
1. Clear EERAS1 and EERAS0 and set EELAT in the EECR.
2. Write the desired data to the desired EEPROM address.
3. Set the EEPGM bit.
4. Wait for time, t
5. Clear EEPGM bit.
6. Wait for time, t
7. Poll the EEPGM bit until it is cleared by the internal timer.
8. Clear EELAT bits.
Freescale Semiconductor, Inc.
For More Information On This Product,
Step 8.
Go to: www.freescale.com
EEPROM
EEPGM
EEFPV
(E)
(C)
, for the programming voltage to fall. Go to
, to program the byte.
Go to Step 7 if AUTO is set.
68HC908AZ32A — Rev 0.0
MOTOROLA
(B)
(D)
(A)