M38500E5H-FP Просмотр технического описания (PDF) - MITSUBISHI ELECTRIC

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производитель

M38500E5H-FP

SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

MITSUBISHI ELECTRIC  

MITSUBISHI MICROCOMPUTERS

3850 Group (Spec. H)

SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

Flash memory control register

b7 b6 b5 b4 b3 b2 b1 b0

Symbol

FMCR

Address

0FFE16

When reset

XXX00001

Bit symbol

Bit name

FMCR0 RY/BY status flag

FMCR1 CPU rewrite mode

select bit (Note 1)

FMCR2 CPU rewrite mode

entry flag

FMCR3 Flash memory reset bit

(Note 2)

FMCR4 User area / Boot area

selection bit

Function

RR WW

0: Busy (being written or erased)

1: Ready

0: Normal mode

(Software commands invalid)

1: CPU rewrite mode

(Software commands acceptable)

0: Normal mode

(Software commands invalid)

1: CPU rewrite mode

(Software commands acceptable)

0: Normal operation

1: Reset

0: User ROM area

1: Boot ROM area

Nothing is assigned.

When write, set “0”. When read, values are indeterminate.

Notes 1: For this bit to be set to “1”, the user needs to write a “0” and then a “1” to it in succession.

2: Effective only when the CPU rewrite mode select bit = 1. Set this bit to “0” subsequently

after setting it to “1” (reset).

Fig. 45 Flash memory control registers

Program in ROM

Start

Single-chip mode, or boot mode

Set CPU mode register (Note 1)

Transfer CPU rewrite mode control

program to internal RAM

Jump to transferred control program in RAM

(Subsequent operations are executed by control

program in this RAM)

*1

Program in RAM

*1

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

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

Check the CPU rewrite mode entry flag

Using software command execute erase,

program, or other operation

Execute read array command or reset flash

memory by setting flash memory reset bit (by

writing “1” and then “0” in succession) (Note 2)

Write “0” to CPU rewrite mode select bit

End

Notes 1: Set bit 6, 7 (Main clock division ratio selection bits ) at CPU mode register (003B16).

2: Before exiting the CPU rewrite mode after completing erase or program operation, always be sure to

execute a read array command or reset the flash memory.

Fig. 46 CPU rewrite mode set/reset flowchart

41

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