AN2156 Freescale Semiconductor / Motorola, AN2156 Datasheet - Page 47

• Manufacturer Part Number: AN2156
• Description: Programming and Erasing FLASH and EEPROM Memories on the MC68HC908AS60A/AZ60A
• Manufacturer: Freescale Semiconductor / Motorola

Question 2
Answer 2
AN2156
MOTOROLA
Why do I need to set up constant timebase?
The EEPROM is actually a FLASH cell surrounded by a logic state
machine. The state machine requires an accurate clock source for
applying high voltage during the erase and program operations.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Did you use our recommended programming and erasing
algorithms in your code?
The EEPROM consists of FLASH memory surrounded by a logic
state machine. Motorola's recommended programming algorithm
ensures that the EEPROM is programmed for sufficient data
retention and in a minimum program time. Motorola does not
guarantee the performance of the EEPROM if the recommended
algorithms are not followed.
Is each step of the programming and erasing algorithms
performed in the right order?
The sequence of the program and erase operations are
interlocked in hardware so only the prescribed order of these
operations can occur. However, other non-EEPROM operations
may occur between the steps shown.
Is the memory block where you want to program/erase
unprotected?
The block protect feature of the EEPROM is present to prevent
unintentional programming or erasing. The block protect bits must
be cleared such that the memory to be erased or programmed is
unprotected.
Are delay times such as t
within the specification?
Timing is critical to ensure proper EEPROM operation. Delay
times that are too long or too short can alter the EEPROM
performance to the point where it does not work or is not reliable.
Motorola does not guarantee EEPROM performance if the wrong
delay times are used.
Is the correct EEPROM register being written to enable erase or
program?
The MC68HC908AS60A/AZ60A has two EEPROM arrays with
two separate sets of control and block protect registers. Make sure
the appropriate register is being addressed.
Go to: www.freescale.com
EEBYTE
, t
EEPROM Frequently Asked Questions
EEBULK
, t
EEBLOCK
Application Note
, t
EEFPV
, etc.,
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