AN1827 Freescale Semiconductor / Motorola, AN1827 Datasheet - Page 21

• Manufacturer Part Number: AN1827
• Description: Programming and Erasing FLASH Memory on the MC68HC908AS60
• Manufacturer: Freescale Semiconductor / Motorola

Frequently Asked Questions
AN1827
MOTOROLA
Question 1
Answer 1
These questions and answers are designed to help the user with
frequent concerns.
I cannot program/erase FLASH memory at all. What should I consider to
make my program/erase code work?
Check the following:
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Freescale Semiconductor, Inc.
For More Information On This Product,
Did you use the smart programming algorithm in your
programming code?
The smart programming algorithm ensures that the FLASH is
programmed for sufficient data retention and in minimum program
time. Furthermore, not following this algorithm can lead to
overprogramming, which risks program disturb. The use of the
smart programming algorithm is highly recommended. (Refer to
Page Program/Margin Read
Is each step of the smart programming algorithm (or erase
algorithm) 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-FLASH operations may
occur between the steps shown.
Is the memory block where you want to program/erase
unprotected?
The block protect feature of the FLASH is present to prevent
unintentional programming or erasing. The block protect bits must
be set such that the memory to be erased or programmed is
unprotected. The only way to override the block protect bits is to
apply voltage V
algorithms. (Refer to
specification?
Timing is critical to ensure proper FLASH operation. Delay times
that are too long or too short can alter the FLASH performance to
the point where it does not work or is not reliable. Motorola does
Are delay times such as t
Go to: www.freescale.com
HI
on IRQ during the erase and program
Block
Step
Protection.)
, t
Algorithm.)
Erase
, t
HVD
Frequently Asked Questions
, etc., within the
Application Note
21