S-25C320A/640A H Series

Seiko Instruments Inc.

10



Instruction Setting

Table 14 is the list of instruction for the S-25C320A/640A. The instruction is able to be input by changing the CS pin “H”

to “L”. Input the instruction in the MSB first. Each instruction code is organized with 1-byte as shown below. If the

S-25C320A/640A receives any invalid instruction code, the device goes in the non-select status.

Table 14 Instruction Set

Instruction

Operation

Instruction code

Address

Data

SCK input clock

1 to 8

SCK input clock

9 to 16

SCK input clock

17 to 24

SCK input clock

25 to 32

WREN

Write enable

0000 0110

−

−

−

WRDI

Write disable

0000 0100

−

−

−

RDSR

Read the status register

0000 0101

b7 to b0 output

*1

−

−

WRSR

Write in the status register

0000 0001

b7 to b0 input

−

−

READ

Read memory data

0000 0011

A15 to A8

*2

A7 to A0

D7 to D0 output

*3

WRITE

Write memory data

0000 0010

A15 to A8

*2

A7 to A0

D7 to D0 input

*1. Sequential data reading is possible.

*2. In the S-25C320A, the higher addresses A15 to A12 = Don’t care.

In the S-25C640A, the higher addresses A15 to A13 = Don’t care.

*3. After outputting data in the specified address, data in the following address is output.