Datasheet

FLASH Memory (FLASH)
FLASH Block Protect Register
MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
MOTOROLA FLASH Memory (FLASH) 53
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4.9 FLASH Block Protect Register
The FLASH block protect register is implemented as a byte within the
FLASH memory, and therefore can only be written during a
programming sequence of the FLASH memory. The value in this register
determines the starting address of the protected range within the FLASH
memory.
BPR[7:0] — FLASH Protection Register Bits [7:0]
These eight bits in FLBPR represent bits [13:6] of a 16-bit memory
address. Bits [15:14] are logic 1s and bits [5:0] are logic 0s.
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 XX00, XX40, XX80,
or XXC0 within the FLASH memory. See Figure 4-4 and Table 4-1.
Figure 4-4. FLASH Block Protect Start Address
Address: $FFBE
Bit 7654321Bit 0
Read:
BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 BPR0
Write:
Reset:UUUUUUUU
U = Unaffected by reset. Initial value from factory is 1.
Write to this register is by a programming sequence to the FLASH memory.
Figure 4-3. FLASH Block Protect Register (FLBPR)
0 0 00011
FLBPR VALUE
START ADDRESS OF
16-BIT MEMORY ADDRESS
FLASH BLOCK PROTECT
0