Datasheet
Memory
MC9S08GT16A/GT8A Data Sheet, Rev. 1
Freescale Semiconductor 59
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 Note
(1)
1
Background commands can be used to change the contents of these bits in FPROT.
Note
(1)
Note
(1)
Note
(1)
Note
(1)
Note
(1)
Note
(1)
Note
(1)
Reset This register is loaded from nonvolatile location NVPROT during reset.
Figure 4-8. FLASH Protection Register (FPROT)
Table 4-10. FPROT 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 FPS2:FPS0 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 4-9. FLASH Status Register (FSTAT)
Table 4-11. FSTAT Field Descriptions
Field Description
7
FCBEF
FLASH Command Buffer Empty Flag — The FCBEF bit is used to launch commands. It also indicates that the
command buffer is empty so that a new command sequence can be executed when performing burst
programming. The FCBEF bit is cleared by writing a 1 to it or when a burst program command is transferred to
the array for programming. Only burst program commands can be buffered.
0 Command buffer is full (not ready for additional commands).
1 A new burst program command may be written to the command buffer.
6
FCCF
FLASH Command Complete Flag — FCCF is set automatically when the command buffer is empty and no
command is being processed. FCCF is cleared automatically when a new command is started (by writing 1 to
FCBEF to register a command). Writing to FCCF has no meaning or effect.
0 Command in progress
1 All commands complete