R5F21133DFP RENESAS [Renesas Technology Corp], R5F21133DFP Datasheet - Page 206

• Manufacturer Part Number: R5F21133DFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY/R8C/Tiny SERIES
• Manufacturer: RENESAS [Renesas Technology Corp]

R8C/13 Group
Rev.1.20
REJ09B0111-0120
19.7 Flash Memory Version
19.7.1 CPU Rewrite Mode
Before entering CPU rewrite mode (EW0 mode), select 5MHz or below for the CPU clock using the
CM06 bit in the CM0 register and the CM16 to CM17 bits in the CM1 register. This usage note is not
needed for EW1 mode.
The following instructions cannot be used in EW0 mode because the flash memory internal data is
referenced: UND, INTO and BRK instructions.
Write “0” to the corresponding bits before writing “1” when setting the FMR01, FMR02, and FMR11
bits to ”1”. Do not generate an interrupt between writing “0” and “1”.
In EW0 mode, if the power supply voltage drops while rewriting any block in which the rewrite control
program is stored, the flash memory may not be able to be rewritten because the rewrite control
program cannot be rewritten correctly. In this case, use stnadard serial I/O mode.
Since the CPU stops and cannot return when setting the FMSTP bit in the FMR0 register to “1” (flash
memory stops) during erase suspend in EW1 mode, do not set the FMSTP bit to “1”.
Do not enter stop mode or wait mode during erase-suspend.
Jan 27, 2006
Operation Speed
Instructions Diabled Against Use
How to Access
Rewriting User ROM Area
Reset Flash Memory
Entering Stop Mode or Wait Mode
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19. Usage Notes