M34C00

4/15

SCL

SDA

SCL

SDA

SDA

START

Condition

SDA

Input

SDA

Change

AI00792B

STOP

Condition

1

23

7

89

MSB

ACK

START

Condition

SCL

1

23

7

89

MSB

ACK

STOP

Condition

must change

driven Low.

Memory Addressing

To start communication between the bus master

and the slave device, the bus master must initiate

a Start condition. Following this, the bus master

sends the 8-bit byte, shown in Table 3, on Serial

Data (SDA) (most significant bit first). This

consists of the 7-bit Device Select code, and the

Read/Write bit (RW).

To address the memory array, the 4-bit Device

Type Identifier is 1010b. To address the Protection

Register, it is 0110b, as shown in Table 3.

set to 1 for Read and 0 for Write operations. If a

match occurs on the Device Select code, the

corresponding device gives an acknowledgment

device does not match the Device Select code, it

deselects itself from the bus, and goes into Stand-

by mode.

Memory Partitioning

The memory is divided in three arrays:

s

Array-0: Write-protectable Array (00h to 0Fh)

s

Array-1: EEPROM Array (10h to 1Fh)

s

Array-2: Non-Erasable Memory Array (20h to

2Fh)

The 4 least significant bits of the address byte

determine the byte that is to be addressed within

the given array. The next 2 more significant

address bits determine the array that is to be

addressed (Array-0, Array-1, Array-2 or Invalid).

The 2 most significant address bits are Don’t Care.

If the address is of the form xx11xxxx, the device

recognises that an attempt is being made to