s908gr32ag3vfa Freescale Semiconductor, Inc, s908gr32ag3vfa Datasheet - Page 42

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

Memory
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more information.
2.6.2 FLASH-1 Control and Block Protect Registers
The FLASH-1 array has two registers that control its operation, the FLASH-1 control register (FL1CR) and
the FLASH-1 block protect register (FL1BPR).
2.6.2.1 FLASH-1 Control Register
The FLASH-1 control register (FL1CR) controls FLASH program and erase operations.
HVEN — High-Voltage Enable Bit
MASS — Mass Erase Control Bit
ERASE — Erase Control Bit
PGM — Program Control Bit
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for
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unauthorized users.
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.
Setting this read/write bit configures the FLASH-1 array for mass erase operation.
This read/write bit configures the memory for erase operation. ERASE is interlocked with the PGM bit
such that both bits cannot be equal to 1 or set to 1 at the same time.
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 = High voltage enabled to array and charge pump on
0 = High voltage disabled to array and charge pump off
1 = MASS erase operation selected
0 = MASS erase operation unselected
1 = Erase operation selected
0 = Erase operation unselected
1 = Program operation selected
0 = Program operation unselected
Address:
A security feature prevents viewing of the FLASH contents.
Reset:
Read:
Write:
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
$FE08
Bit 7
0
0
Figure 2-3. FLASH-1 Control Register (FL1CR)
= Unimplemented
6
0
0
5
0
0
NOTE
4
0
0
HVEN
3
0
MASS
2
0
(1)
ERASE
1
0
Freescale Semiconductor
PGM
Bit 0
0