24LC16B datasheet(7/24 Pages) MICROCHIP

7 / 24 page

 2018-2022 Microchip Technology Inc. and its subsidiaries

DS20006054B-page 7

24LC16B

5.0

DEVICE ADDRESSING

A control byte is the first byte received following the

Start condition from the host device. The control byte

consists of a four-bit control code. For the 24LC16B,

this is set as ‘

1010’ binary for read and write opera-

tions. The next three bits of the control byte are the

block-select bits (B2, B1, B0). They are used by the

host

device

select

which

the

eight

256 word-blocks of memory are to be accessed.

These bits are in effect the three Most Significant bits

(MSb) of the word address. It should be noted that the

protocol limits the size of the memory to eight blocks

of 256 words, therefore, the protocol can support only

one 24LC16B per system. The combination of the

4-bit control code and the next three bits are called the

client address.

The last bit of the control byte is the Read/Write (R/W)

bit and it defines the operation to be performed. When

set to ‘

1’, a read operation is selected. When set to ‘0’,

a write operation is selected. Following the Start

condition, the 24LC16B monitors the SDA bus,

checking the device type identifier being transmitted

and, upon receiving a valid client address and the R/W

bit, the client device outputs an Acknowledge signal on

the SDA line. Depending on the state of the R/W bit, the

24LC16B will select a read or write operation.

The next byte received defines the address of the first

data byte within the selected block (Figure 5-2). The

word address byte uses all eight bits.

FIGURE 5-1:

CONTROL BYTE

ALLOCATION

FIGURE 5-2:

ADDRESS SEQUENCE BIT ASSIGNMENTS

Operation

Control

Code

Block Select

R/W

Read

1010

Block Address

Write

1010

Block Address

B2 B1 B0 R/W ACK

Start bit

Read/Write bit

Client Address

Acknowledge bit

Control Code

Block

Select

bits

010

0 R/W

••

•

••

Control byte

Word Address byte

Control

Code

Block

Select

bits

24LC16B Datasheet(PDF) 7 Page - Microchip Technology

24LC16B Datasheet(HTML) 7 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Datasheet Download

Link URL