MC68HC908GR16 Datasheet, PDF (42/310 Pages) Motorola, Inc – Microcontrollers

Memory
Freescale Semiconductor, Inc.
NOTE:
CAUTION:
5. Set the HVEN bit.
6. Wait for a time, t_PGS (minimum 5 µs).
7. Write data to the FLASH address to be programmed.
8. Wait for a time, t_PROG (minimum 30 µs).
9. Repeat step 7 and 8 until all the bytes within the row are programmed.
10. Clear the PGM bit.⁽¹⁾
11. Wait for a time, t_NVH (minimum 5 µs).
12. Clear the HVEN bit.
13. After time, t_RCV (minimum 1 µs), the memory can be accessed in read mode
again.
This program sequence is repeated throughout the memory until all data is
programmed.
Programming and erasing of FLASH locations can not be performed by code being
executed from the same FLASH array. While these operations must be performed
in the order shown, other unrelated operations may occur between the steps. Care
must be taken within the FLASH array memory space such as the COP control
register (COPCTL) at $FFFF.
It is highly recommended that interrupts be disabled during program/ erase
operations.
Do not exceed t_PROG maximum or t_HV maximum. t_HV is defined as the cumulative
high voltage programming time to the same row before next erase. t_HV must satisfy
this condition:
t_NVX = t_NVH + t_PGS + (t_PROG x 32) <= t_HV maximum
Refer to 20.18 Memory Characteristics.
The time between programming the FLASH address change (step 7 to step 7),
or the time between the last FLASH programmed to clearing the PGM bit (step 7
to step 10) must not exceed the maximum programming time, t_PROG maximum.
Be cautious when programming the FLASH array to ensure that non-FLASH
locations are not used as the address that is written to when selecting either the
desired row address range in step 3 of the algorithm or the byte to be programmed
in step 7 of the algorithm. This applies particularly to $FFD4–$FFDF.
Data Sheet
42
Memory
For More Information On This Product,
Go to: www.freescale.com
MC68HC908GR16 — Rev. 1.0
MOTOROLA