Datasheet

Chapter 4 Memory
MC9S08AW60 Data Sheet, Rev 2
Freescale Semiconductor 61
4.6.4 FLASH Protection Register (FPROT and NVPROT)
During reset, the contents of the nonvolatile location NVPROT are copied from FLASH into FPROT. This
register may be read at any time.
• If FPDIS = 0, then protection can be increased (in other words, a smaller value of FPS can be
written).
• If FPDIS = 1, then writes do not change protection.
Figure 4-9. FLASH Protection Register (FPROT)
4.6.5 FLASH Status Register (FSTAT)
Bits 3, 1, and 0 always read 0 and writes have no meaning or effect. The remaining five bits are status bits
that can be read at any time. Writes to these bits have special meanings that are discussed in the bit
descriptions.
76543210
R FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1 FPDIS
W
(1)
1
Background commands can be used to change the contents of these bits in FPROT.
(1) (1) (1) (1) (1) (1) (1)
Reset This register is loaded from nonvolatile location NVPROT during reset.
Table 4-11. FPROT Register Field Descriptions
Field Description
7:1
FPS[7:1]
FLASH Protect Select Bits — When FPDIS = 0, this 7-bit field determines the ending address of unprotected
FLASH locations at the high address end of the FLASH. Protected FLASH locations cannot be erased or
programmed.
0
FPDIS
FLASH Protection Disable
0 FLASH block specified by FPS[7:1] is block protected (program and erase not allowed).
1 No FLASH block is protected.
76543210
R
FCBEF
FCCF
FPVIOL FACCERR
0 FBLANK 0 0
W
Reset 11000000
= Unimplemented or Reserved
Figure 4-10. FLASH Status Register (FSTAT)