38K2 datasheet(122/358 Pages) RENESAS

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FUNCTIONAL DESCRIPTION

Rev.2.00

Oct 15, 2006

page 103 of 130

38K2 Group

REJ09B0338-0200

HARDWARE

Fig. 148 CPU rewrite mode set/release flowchart

End

Start

Execute read array command or reset flash

memory by setting flash memory reset bit (by

writing “1” and then “0” in succession) (Note 3)

Single-chip mode or Boot mode (Note 1)

Set CPU mode register (Note 2)

Using software command execute erase,

program, or other operation

Jump to control program transferred in memory

other than internal flash memory

(Subsequent operations are executed by control

program in this memory)

Transfer CPU rewrite mode control program to

memory other than internal flash memory

Notes 1: When starting the MCU in the single-chip mode or memory expansion mode, supply

4.5 V to 5.25 V to the CNVss pin until checking the CPU rewrite mode entry flag.

2: Set the system clock division ration selection bits of CPU mode register (bits 6 and

7 at address 003B16).

3: Before exiting the CPU rewrite mode after completing erase or program operation,

always be sure to execute the read array command or reset the flash memory.

Write “0” to CPU rewrite mode select bit

Set CPU rewrite mode select bit to “1” (by

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

Check CPU rewrite mode entry flag

38K2 Datasheet(PDF) 122 Page - Renesas Technology Corp