Data Sheet M15902EJ2V0DS

8

µPD23C256112A

Operation Commands

The following six operation settings are possible by inputting commands from I/O pins.

Command

HEX

I/O7

I/O6

I/O5

I/O4

I/O3

I/O2

I/O1

I/O0

Command receivable

during Busy

Read mode(1)

00H

L

L

L

L

L

L

L

L

Read mode(2)

01H

L

L

L

L

L

L

L

H

Read mode(3)

Note1

50H

L

H

L

H

LL

LL

Reset

Note2

FFH

HH

HHH

HHH

Status read

70H

L

H

H

H

L

L

L

L

ID read

Note3

90H

H

L

L

H

LL

LL

Notes 1. The data output in read mode (3) is all FFH.

2. The only command that can be executed when the device is Busy is the reset command. Do not set any

of the other commands while the device is Busy.

3. For ID read, input “00H” during the first address cycle after setting a command.

I/O Pin Correspondence Table during Address Input Cycle (Address Setting)

(1) When 00H or 01H command is set [Read mode (1), Read mode (2)]

Command

I/O7

I/O6

I/O5

I/O4

I/O3

I/O2

I/O1

I/O0

1st address cycle

A7

A6

A5

A4

A3

A2

A1

A0

2nd address cycle

A16

A15

A14

A13

A12

A11

A10

A9

3rd address cycle

A24

A23

A22

A21

A20

A19

A18

A17

(2) When 50H command is set [Read mode (3)]

Command

I/O7

I/O6

I/O5

I/O4

I/O3

I/O2

I/O1

I/O0

1st address cycle

×××

×

A3

A2

A1

A0

2nd address cycle

A16

A15

A14

A13

A12

A11

A10

A9

3rd address cycle

A24

A23

A22

A21

A20

A19

A18

A17

Remarks 1. A0 to A24 are internal addresses.

2. Internal address A8 is set internally with command 00H or 01H.

3. When 50H command is set [read mode (3)], the I/O4, I/O5, I/O6, and I/O7 inputs of the 1st address