NXP Semiconductors
FXTH87E
FXTH87E, Family of Tire Pressure Monitor Sensors
6.9.5 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.
Table 24.ꢀFLASH status register (FSTAT) (address $1825)
Bit
R
7
FCBEF
1
6
5
FPVIOL
0
4
FACCERR
0
3
2
1
0
FCCF
0
FBLANK
0
0
W
Reset
1
0
0
0
0
= Reserved
Table 25.ꢀFSTAT register field descriptions
Field
Description
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.
7
FCBEF
0ꢀCommand buffer is full (not ready for additional commands)
1ꢀA new burst program command can be written to the command buffer
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.
6
FCCF
0ꢀCommand in progress
1ꢀAll commands complete
Protection Violation Flag — FPVIOL is set automatically when FCBEF is cleared to register a command that
attempts to erase or program a location in a protected block (the erroneous command is ignored). FPVIOL
is cleared by writing a 1 to FPVIOL.
5
FPVIOL
0ꢀNo protection violation
1ꢀAn attempt was made to erase or program a protected location
Access Error Flag — FACCERR is set automatically when the proper command sequence is not obeyed
exactly (the erroneous command is ignored), if a program or erase operation is attempted before the FCDIV
register has been initialized, or if the MCU enters STOP while a command was in progress. For a more
detailed discussion of the exact actions that are considered access errors, see Section 6.7.5 "Access
errors". FACCERR is cleared by writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or
effect.
4
FACCERR
0ꢀNo access error
1ꢀAn access error has occurred
FLASH Verified as All Blank (erased) Flag — FBLANK is set automatically at the conclusion of a blank
check command if the entire FLASH array was verified to be erased. FBLANK is cleared by clearing FCBEF
to write a new valid command. Writing to FBLANK has no meaning or effect.
2
0ꢀAfter a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the FLASH array is not
completely erased
FBLANK
1ꢀAfter a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the FLASH array is
completely erased (all 0xFF)
FXTH87ERM
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© NXP B.V. 2019. All rights reserved.
Reference manual
Rev. 5.0 — 4 February 2019
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