R8C33A Datasheet, PDF (533/617 Pages) Renesas Technology Corp – MCU M16C FAMILY / R8C/Tiny SERIES

Under development ^{Preliminary specification}
Specifications in this manual are tentative and subject to change.
R8C/33A Group
31. Flash Memory
31.4.8 How to Set and Exit Each Mode
Figure 31.3 shows How to Set and Exit EW0 Mode and Figure 31.4 shows How to Set and Exit EW0 Mode
(When Rewriting Data Flash) and EW1 Mode.
EW0 Mode Execution Procedure
(When Rewriting User ROM)
Rewrite control program
After writing 0 to the FMR01 bit,
write 1 (CPU rewrite mode enabled) ⁽¹⁾
Transfer the rewrite mode program that uses
CPU rewrite mode to the RAM
Jump to the rewrite control program transferred
to the RAM
(The subsequent process is executed by the
rewrite control program in the RAM)
Execute software commands
Write 0 (CPU rewrite mode disabled) to
the FMR01 bit
Jump to the specified address in the flash memory
FMR01: Bit in FMR0 register
Note:
To set the FMR01 bit to 1, first write 0 and then 1 immediately. Do not generate an interrupt between writing 0 and writing 1.
Writing to the FMR01 bit must be performed in the RAM.
Figure 31.3 How to Set and Exit EW0 Mode
EW0 Mode Execution Procedure (When Rewriting Data Flash)
EW1 Mode Execution Procedure
Program in ROM
After writing 0 to the FMR01 bit,
write 1 (CPU rewrite mode enabled) ⁽¹⁾
After writing 0 to the FMR02 bit,
write 1 (EW1 mode) ⁽²⁾
Execute software commands
Write 0 (CPU rewrite mode disabled) to
the FMR01 bit
Figure 31.4
FMR01, FMR02: Bits in FMR0 register
Notes:
1. To set the FMR01 bit to 1, first write 0 and then 1 immediately.
Do not generate an interrupt between writing 0 and writing 1.
2. Not required when rewriting the data flash in EW0 mode.
How to Set and Exit EW0 Mode (When Rewriting Data Flash) and EW1 Mode
REJ09B0455-0010 Rev.0.10 Feb 29, 2008
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