MC908GR32AVFAE Datasheet, PDF (51/314 Pages) Freescale Semiconductor, Inc – Microcontrollers

FLASH-2 Memory (FLASH-2)
HVEN — High-Voltage Enable Bit
This read/write bit enables the charge pump to drive high voltages for program and erase operations
in the array. HVEN can only be set if either PGM = 1 or ERASE = 1 and the proper sequence for
program or erase is followed.
1 = High voltage enabled to array and charge pump on
0 = High voltage disabled to array and charge pump off
MASS — Mass Erase Control Bit
Setting this read/write bit configures the FLASH-2 array for mass or page erase operation.
1 = Mass erase operation selected
0 = Page erase operation selected
ERASE — Erase Control Bit
This read/write bit configures the memory for erase operation. ERASE is interlocked with the PGM bit
such that both bits cannot be set at the same time.
1 = Erase operation selected
0 = Erase operation unselected
PGM — Program Control Bit
This read/write bit configures the memory for program operation. PGM is interlocked with the ERASE
bit such that both bits cannot be equal to 1 or set to 1 at the same time.
1 = Program operation selected
0 = Program operation unselected
2.7.2.2 FLASH-2 Block Protect Register
The FLASH-2 block protect register (FL2BPR) is implemented as a byte within the FLASH-1 memory;
therefore, can only be written during a FLASH-1 programming sequence. The value in this register
determines the starting location of the protected range within the FLASH-2 memory.
Address:
Read:
Write:
Reset:
$FF81
Bit 7
6
5
4
3
2
1
BPR7
BPR6
BPR5
BPR4
BPR3
BPR2
BPR1
Unaffected by reset
Figure 2-8. FLASH-2 Block Protect Register (FL2BPR)
Bit 0
BPR0
NOTE
The FLASH-2 block protect register (FL2BPR) controls the block protection
for the FLASH-2 array. However, FL2BPR is implemented within the
FLASH-1 memory array and therefore, the FLASH-1 control register
(FL1CR) must be used to program/erase FL2BPR.
FL2BPR[7:0] — Block Protect Register Bits 7 to 0
These eight bits represent bits [14:7] of a 16-bit memory address. Bit 15 is a 0 and bits [6:0] are 0s.
The resultant 16-bit address is used for specifying the start address of the FLASH-2 memory for block
protection. FLASH-2 is protected from this start address to the end of FLASH-2 memory at $7FFF.
With this mechanism, the protect start address can be $XX00 and $XX80 (128 byte page boundaries)
within the FLASH-2 array.
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Freescale Semiconductor
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