Datasheet

Section 17 EEPROM

Rev. 6.00 Mar. 24, 2006 Page 292 of 412

REJ09B0142-0600

17.4.6 Slave Addressing

The EEPROM device receives a 7-bit slave address and a 1-bit R/W code following the generation

of the start conditions. The EEPROM enables the chip for a read or a write operation with this

operation.

The slave address consists of a former 4-bit device code and latter 3-bit slave address as shown in

table 17.2. The device code is used to distinguish device type and this LSI uses "1010" fixed code

in the same manner as in a general-purpose EEPROM. The slave address code selects one device

out of all devices with device code 1010 (8 devices in maximum) which are connected to the I

bus. This means that the device is selected if the inputted slave address code received in the order

of A2, A1, A0 is equal to the corresponding slave address reference register (ESAR).

The slave address code is stored in the address H'FF09 in the EEPROM. It is transferred to ESAR

from the slave address register in the memory array during 10 ms after the reset is released. An

access to the EEPROM is not allowed during transfer.

The initial value of the slave address code written in the EEPROM is H'00. It can be written in the

range of H'00 to H'07. Be sure to write the data by the byte write method.

The next one bit of the slave address is the R/W code. 0 is for a write and 1 is for a read.

The EEPROM turns to a standby state if the device code is not "1010" or slave address code

doesn’t coincide.

Table 17.2 Slave Addresses

Bit

Bit name

Initial

Value

Setting

Value

Remarks

7 Device code D3  1

6 Device code D2  0

5 Device code D1  1

4 Device code D0  0

3 Slave address code A2 0 A2 The initial value can be changed

2 Slave address code A1 0 A1 The initial value can be changed

1 Slave address code A0 0 A0 The initial value can be changed