FOR AUTOMOTIVE 105

°C OPERATION 2-WIRE SERIAL E

S-24CS01A/02A/04A H Series

11

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).

Slave Address

1

0

1

0

A2

A1

A0

R/W

Device Code

LSB

MSB

S-24CS01A/02A

Slave / Page

Address

Device Code

S-24CS04A

1

0

1

0

A2

A1

P0

R/W

MSB

LSB

Figure 11 Device Address