M38K09RFS datasheet(239/328 Pages) RENESAS

239 / 328 page

2.13 Flash memory

Rev.2.00

Oct 05, 2006

page 110 of 111

38K0 Group

REJ09B0337-0200

APPLICATION

Fig. 2.13.9 CPU rewrite mode beginning/release flowchart

START

Single-chip mode or boot mode (Note 1)

Set CPU mode register (Note 2)

Transfer CPU rewrite mode control

program to built-in RAM

END

Jump to transferred control program on RAM

(The following operations are controlled by

the control program on this RAM)

Set “1” to CPU rewrite mode select bit

(by writing “0” and then “1” in succession)

Check CPU rewrite mode entry flag

Using software command execute erase,

program, or other operation

Execute read command or set flash

memory reset bit (by writing “0” and then “

1” in succession) (Note 3)

Set “0” to CPU rewrite mode select bit

Notes 1: When MCU starts in the single-chip mode, it is necessary to apply

4.50 to 5.25 V to dhe CNVss pin until confirming of the CPU

rewrite mode entry flag.

2: Set bits 6 and 7 (system clock division ratio selection bits) of the

CPU mode register (address 003B16).

3: Before releasing the CPU rewrite mode after completing erase or

program operation, always be sure to execute the read array

command or reset the flash memory.

M38K09RFS Datasheet(PDF) 239 Page - Renesas Technology Corp