Datasheet

MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
50 FLASH Memory (FLASH) MOTOROLA
FLASH Memory (FLASH)
NON-DISCLOSURE AGREEMENT REQUIRED
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 location within the 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 being programmed
(1)
.
8. Wait for time, t
PROG
(minimum 30 µs).
9. Repeat step 7 and 8 until all desired bytes within the row are
programmed.
10. Clear the PGM bit
(1)
.
11. Wait for time, t
nvh
(minimum 5 µs).
12. Clear the HVEN bit.
13. After time, t
rcv
(typical 1 µs), the memory can be accessed in read
mode again.
NOTE: The COP register at location $FFFF should not be written between steps
5-12, when the HVEN bit is set. Since this register is located at a valid
FLASH address, unpredictable behavior may occur if this location is
written while HVEN is set.
This program sequence is repeated throughout the memory until all data
is programmed.
NOTE: Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order shown, other unrelated operations may
occur between the steps. Do not exceed t
PROG
maximum, see 18.14
Memory Characteristics.
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.