mc68hc908jw32 Freescale Semiconductor, Inc, mc68hc908jw32 Datasheet - Page 38

• Manufacturer Part Number: mc68hc908jw32
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Memory
2.5.7 FLASH Block Protect Register
The FLASH block protect register is implemented as an 8-bit I/O register. The value in this register
determines the starting address of the protected range within the FLASH memory.
BPR[7:0] — FLASH Block Protect Bits
38
BPR[7:1] represent bits [15:9] of a 16-bit memory address. Bits [8:0] are logic 0’s.
BPR0 is used only for BPR[7:0] = $FF, for no block protection.
The resultant 16-bit address is used for specifying the start address of the FLASH memory for block
protection. The FLASH is protected from this start address to the end of FLASH memory, at $FFFF.
With this mechanism, the protect start address can be X000, X200, etc. (at page boundaries — 512
bytes) within the FLASH memory.
Examples of protect start address:
Address:
1. The 48-byte user vectors ($FFD0–$FFFF), which are always protected.
Reset:
Read:
Write:
Start address of FLASH block protect
(0111 000x)
(0111 001x)
(0111 010x)
(1110 111x)
$EE or $EF
$70 or $71
$72 or $73
$74 or $75
BPR[7:0]
$F0 - $FF
$00–$70
$FE09
BPR7
Bit 7
0
Figure 2-5. FLASH Block Protect Register (FLBPR)
Table 2-2 FLASH Block Protect Range
BPR6
6
0
MC68HC908JW32 Data Sheet, Rev. 5
BPR5
5
0
The entire FLASH memory is NOT protected.
(The entire FLASH memory is protected.)
The entire FLASH memory is protected.
and so on...
BPR4
4
0
BPR[7:1]
Protected Range
$EE00 to $FFFF
$7000 to $FFFF
$7200 to $FFFF
$7400 to $FFFF
BPR3
3
0
16-bit memory address
BPR2
0 0 0 0 0 0 0 0 0
2
0
BPR1
1
0
(1)
Freescale Semiconductor
BPR0
Bit 0
0