MC68HC908GT16 Datasheet, PDF (182/412 Pages) Motorola, Inc – Microcontrollers

FLASH Memory
11.7 FLASH Program/Read Operation
Programming of the FLASH memory is done on a row basis. A row
consists of 32 consecutive bytes starting from addresses $XX00,
$XX20, $XX40, $XX60, $XX80, $XXA0, $XXC0, and $XXE0. Use this
step-by-step procedure to program a row of FLASH memory
(Figure 11-2 is a flowchart representation):
NOTE: In order to avoid program disturbs, the row must be erased before any
byte on that row is programmed.
1. Set the PGM bit. This configures the memory for program
operation and enables the latching of address and data for
programming.
2. Read from the FLASH block protect register.
3. Write any data to any FLASH address within the row address
range desired.
4. Wait for a time, t_NVS (minimum 10 µs).
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.⁽¹⁾
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.
Technical Data
182
1. The time between each FLASH address change, or the time between the last FLASH address
programmed to clearing PGM bit, must not exceed the maximum programming time, t_PROG
maximum.
MC68HC908GT16 • MC68HC908GT8 — Rev. 2
FLASH Memory
MOTOROLA