AN1827 Freescale Semiconductor / Motorola, AN1827 Datasheet - Page 25

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

AN1827
MOTOROLA
Question 13
Question 14
Question 15
Question 16
Question 17
Answer 13
Answer 14
Answer 15
Answer 16
Answer 17
I’m sending external data serially into the MC68HC908AS60 for
programming. How can I speed up this process?
If you run the MC68HC908AS60 at a higher bus speed, you can improve
the non-FLASH overhead during programming.
If I program FLASH with 2-MHz bus frequency, can I read the FLASH
with 8-MHz bus frequency without any problems?
Yes. The FLASH will meet all specifications, including data retention
performance, if the FLASH is programmed/erased and used within
specification limits.
Why is the maximum number of program attempts (fls
This limit is set high to account for the worst case manufacturing process
variations, ensuring that the slowest FLASH bit will still program. On
average, the page program times are much faster than this worst case
limit.
The program/erase operation is not successful in the monitor mode.
The FLASH memory is protected in the monitor mode to make it difficult
for unauthorized users to view the memory contents. Before
programming/erasing FLASH, the security feature on the part must be
"broken" to view the FLASH contents. When an attempt to break security
fails, the FLASH is not addressed during reads and invalid data will be
observed. Refer to the monitor ROM section, which describes how to
break security, in the MC68HC908AS60 Advance Information, Motorola
document order number MC68HC908AS60/D.
I have failed to break security in monitor mode. Can I execute a bulk
erase?
Yes. Bulk erase is the only FLASH operation to attempt when failing to
break security in monitor mode. Make sure the block protect feature is
not asserted or override it to bulk erase the device.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
Frequently Asked Questions
Pulses
Application Note
) so high?
25