M306H5MG-XXXFP Datasheet, PDF (318/324 Pages) Renesas Technology Corp – SNGLE-CHIP 16-BIT CMOS MICROCOMPUTER with DATA ACQUISITION CONTROLLER

M306H5MG-XXXFP/MC-XXXFP/FGFP
EW1 Mode
• Make sure that any interrupt which has a vector in the variable vector table or address match
interrupt will not be accepted during the auto program or auto erase period.
• Avoid using watchdog timer interrupts.
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• The NMI interrupt can be used because the FMR0 register and FMR1 register are initialized when
this interrupt occurs. The jump address for the interrupt service routine should be set in the fixed
vector table.
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Because the rewrite operation is halted when a NMI interrupt occurs, the rewrite program must be
executed again after exiting the interrupt service routine.
How to access
To set the FMR01, FMR02, or FMR11 bit to “1”, write “0” and then “1” in succession. This is necessary
to ensure that no interrupts or DMA transfers will occur before writing “1” after writing “0”. Also only
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when NMI pin is “H” level.
Writing in the user ROM area
EW0 Mode
• If the power supply voltage drops while rewriting any block in which the rewrite control program is
stored, a problem may occur that the rewrite control program is not correctly rewritten and, conse-
quently, the flash memory becomes unable to be rewritten thereafter. In this case, standard serial
I/O or parallel I/O mode should be used.
EW1 Mode
• Avoid rewriting any block in which the rewrite control program is stored.
DMA transfer
In EW1 mode, make sure that no DMA transfers will occur while the FMR0 register’s FMR00 bit = 0
(during the auto program or auto erase period).
Regarding Programming/Erasure Times and Execution Time
As the number of programming/erasure times increases, so does the execution time for software
commands (Program, Block Erase, and Lock Bit Program). Especially when the number of program-
ming/erasure times exceeds 1,000, the software command execution time is noticeably extended.
Therefore, the software command wait time that is set must be greater than the maximum rated value
of electrical characteristics.
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The software commands are aborted by hardware reset 1, hardware reset 2, NMI interrupt, and
watchdog timer interrupt. If a software command is aborted by such reset or interrupt, the block that
was in process must be erased before reexecuting the aborted command.
Rev.1.20 Dec 13, 2005 page 318 of 323
REJ03B0095-0100Z