s908gr32ag3vfa Freescale Semiconductor, Inc, s908gr32ag3vfa Datasheet - Page 52

• Manufacturer Part Number: s908gr32ag3vfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Memory
Decreasing the value in FL2BPR by one increases the protected range by one page (128 bytes).
However, programming the block protect register with $FE protects a range twice that size, 256 bytes, in
the corresponding array. $FE means that locations $7F00–$7FFF are protected in FLASH-2.
The FLASH memory does not exist at some locations. The block protection range configuration is
unaffected if FLASH memory does not exist in that range. Refer to
desired locations are protected.
2.7.3 FLASH-2 Block Protection
Due to the ability of the on-board charge pump to erase and program the FLASH memory in the target
application, provision is made for protecting blocks of memory from unintentional erase or program
operations due to system malfunction. This protection is done by using the FLASH-2 block protection
register (FL2BPR). FL2BPR determines the range of the FLASH-2 memory which is to be protected. The
range of the protected area starts from a location defined by FL2BPR and ends at the bottom of the
FLASH-2 memory ($7FFF). When the memory is protected, the HVEN bit can not be set in either ERASE
or PROGRAM operations.
When the FLASH-2 block protect register is programmed with all 0’s, the entire memory is protected from
being programmed and erased. When all the bits are erased (all 1’s), the entire memory is accessible for
program and erase.
52
In performing a program or erase operation, the FLASH-2 block protect
register must be read after setting the PGM or ERASE bit and before
asserting the HVEN bit.
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
START ADDRESS OF FLASH
BLOCK PROTECT
Figure 2-9. FLASH-2 Block Protect Start Address
FL2BPR[7:0]
$FF
$FE
$FD
$0B
$0A
Table 2-3. FLASH-2 Protected Ranges
$09
$08
$04
$03
$02
$01
$00
↓
↓
0
FLBPR VALUE
NOTE
16-BIT MEMORY ADDRESS
Protected Range
$7E80–$7FFF
$7F00–$7FFF
$0580–$7FFF
$0500–$7FFF
$0480–$7FFF
$0462–$7FFF
$0462–$7FFF
$0462–$7FFF
$0462–$7FFF
$0462–$7FFF
$0462–$7FFF
No Protection
↓
↓
0 0 0 0 0 0 0
Figure 2-1
and make sure that the
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