MC68HC908GR16 Datasheet, PDF (41/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Memory
FLASH Memory (FLASH)
2.6.1.3 FLASH Mass Erase Operation
Use this step-by-step procedure to erase entire FLASH memory to read as logic 1:
1. Set both the ERASE bit, and the MASS bit in the FLASH control register.
2. Read from the FLASH block protect register.
3. Write any data to any FLASH address⁽¹⁾ within the FLASH memory address
range.
4. Wait for a time, t_NVS (minimum 10 µs)
5. Set the HVEN bit.
6. Wait for a time, t_MErase (minimum 4 ms)
7. Clear the ERASE and MASS bits.
8. Wait for a time, t_NVHL (minimum 100 µs)
9. Clear the HVEN bit.
10. After a time, t_RCV (minimum 1 µs), the memory can be accessed again in
read mode.
NOTE: Mass erase is disabled whenever any block is protected (FLBPR does not equal
$FF).
Programming and erasing of FLASH locations cannot be performed by code being
executed from FLASH memory. While these operations must be performed in the
order shown, other unrelated operations may occur between the steps.
2.6.1.4 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.
During the programming cycle, make sure that all addresses being written to fit
within one of the ranges specified above. Attempts to program addresses in
different row ranges in one programming cycle will fail. Use this step-by-step
procedure to program a row of FLASH memory (Figure 2-4 is a flowchart
representation).
NOTE: Only bytes which are currently $FF may be 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).
1. When in monitor mode, with security sequence failed (see 19.3.2 Security), write to the FLASH
block protect register instead of any FLASH address.
MC68HC908GR16 — Rev. 1.0
MOTOROLA
Memory
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Data Sheet
41