MC908AS60ACFU Datasheet, PDF (62/414 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

FLASH-2 Memory
5.3 FLASH-2 Control and Block Protect Registers
The FLASH-2 array has two registers that control its operation, the FLASH-2 Control Register (FL2CR)
and the FLASH-2 Block Protect Register (FL2BPR).
5.3.1 FLASH-2 Control Register
The FLASH-2 Control Register (FL2CR) controls FLASH-2 program and erase operations.
Address: $FE08
Bit 7
6
5
4
3
2
1
Bit 0
Read: 0
0
0
0
HVEN MASS ERASE PGM
Write:
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 5-1. FLASH-2 Control Register (FL2CR)
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
5.3.2 FLASH-2 Block Protect Register
The FLASH-2 Block Protect Register (FL2BPR) is implemented as a byte within the FLASH-1 memory
and therefore can only be written during a FLASH programming sequence. The value in this register
determines the starting location of the protected range within the FLASH-2 memory.
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
62
Freescale Semiconductor