S24CS02A datasheet(12/47 Pages) SII

12 / 47 page

2-WIRE CMOS SERIAL E2PROM

S-24CS01A/02A/04A/08A

Rev.4.4_00

Seiko Instruments Inc.

5. Device Addressing

To start communication, the master device on the system generates a start condition to the bus line. Next,

the master device sends 7-bit device address and a 1-bit read / write instruction code on to the SDA bus.

The 4 most significant bits of the device address are called the "Device Code", and are fixed to "1010".

In S-24CS01A/02A, successive 3 bits are called the "Slave Address". These 3 bits are used to identify a

device on the system bus and are compared with the predetermined value which is defined by the address

input pins (A0, A1 and A2). When the comparison result matches, the slave device responds with an

acknowledge during the 9th clock cycle.

In S-24CS04A, successive 2 bits are called the "Slave Address". These 2 bits are used to identify a device

on the system bus and are compared with the predetermined value which is defined by the address input

pins (A1 and A2). When the comparison result matches, the slave device responds with an acknowledge

during the 9th clock cycle.

The successive 1 bit (P0) is used to define a page address and choose the two 256-byte memory blocks

(Address 000h to 0FFh and 100h to 1FFh).

In S-24CS08A, successive 1 bit is called the “Slave Addrdess”. This 1 bit is used to identify a device on the

system bus and is compared with the predetermined value which is defined by the address input pin (A2).

When the comparison result matches, the slave device responds with an acknowledge during the 9th

clocks cycle.

The successive 2 bits (P1 and P0) are used to define a page address and choose the four 256-byte

memory blocks (Address 000h to 0FFh, 100h to 1FFh, 200h to 2FFh and 300h to 3FFh).

Slave Address

R/W

Device Code

LSB

MSB

S-24CS01A/02A

Slave / Page

Address

Device Code

S-24CS04A

R/W

LSB

MSB

S-24CS08A

Figure 12 Device Address

S24CS02A 데이터시트(PDF) 12 Page - Seiko Instruments Inc