M37754FFCGP Datasheet, PDF (36/68 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER FLASH MEMORY VERSION

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MITSUBISHI MICROCOMPUTERS
M37754FFCGP
M37754FFCHP
SHINGLE-CHIP 16-BIT CMOS MICROCOMPUTER FLASH MEMORY VERSION
Auto erase command
When writing “3016” twice continuously to the flash command regis-
ter, the flash memory control circuit executes the auto erase se-
quence described below for the area specified beforehand by the
erase/program area select bits.
(1) Data “0016" is written to the area to be erased in the flash
memory.
(2) The erasure is executed.
(3) The contents of the erased flash memory is erase-verified one by
one. When the address which is not erased is found, verification
is interrupted, and after the erase command is executed again,
erase-verification is operated again.
(4) When the erasure of all areas specified to be erased, is con-
firmed by erase-verify-operation, the auto erase command is
ended.
The auto erase/erase/program busy flag of the flash memory control
register becomes “1" when auto erase starts, and becomes “0" when
auto erase completes. Accordingly, CPU can recognize the comple-
tion of auto erase by polling this bit.
During auto erase, watchdog timer stops with “FF16” set.
Note: When the flash memory is erased by using the auto erase
command, it is unnecessary to execute the erase and erase
verify commands. Figure 25 shows the flowchart when auto
erase is executed.
DC electric characteristics
Note: The characteristic of the flash memory part are the same as
the standard of the parallel I/O mode.
AC electric characteristics
Note: The characteristics are the same as the standards of the mi-
crocomputer mode.
Reset command
The reset command is a command to discontinue the program,
erase, or the auto erase command on the way. When “FF16” is writ-
ten to the command register two times continuously after “4016,”
“2016,” or “3016” is written to the flash command register, the pro-
gram, erase, or auto erase command becomes invalid (reset), and
the M37754FFCGP and the M37754FFCHP enters the reset mode.
The contents of the memory does not change even if the reset com-
mand is executed.
Auto erase
START
WRITE AUTO-ERASE
COMMAND
3016
WRITE AUTO-ERASE
COMMAND
3016
NOP ! 10
NO
ERASE PROGRAM
BUSY FLAG = 0
YES
DEVICE
PASSED
Fig. 25 Flowchart when program/erase/auto erase is executed (2)
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