EMC1428 datasheet(12/53 Pages) MICROCHIP

12 / 53 page

1°C Multiple Temperature Sensor with HW Thermal Shutdown & Hottest of Thermal Zones

Data Sheet

DS20005275A-page 12

 2014 Microchip Technology Inc.

Chapter 3 System Management Bus Interface Protocol

3.1

System Management Bus Interface Protocol

The EMC1428 communicate with a host controller, such as a Microchip SIO, through the SMBus. The

SMBus is a two-wire serial communication protocol between a computer host and its peripheral

devices. A detailed timing diagram is shown in Figure 3.1.

The EMC1428 are SMBus 2.0 compatible and support Send Byte, Read Byte, Write Byte, Receive

Byte, and the Alert Response Address as valid protocols as shown below.

All of the below protocols use the convention in Table 3.1.

Attempting to communicate with the EMC1428 SMBus interface with an invalid slave address or invalid

protocol will result in no response from the device and will not affect its register contents. Stretching

of the SMCLK signal is supported, provided other devices on the SMBus control the timing.

3.2

Write Byte

The Write Byte is used to write one byte of data to the registers as shown below Table 3.2:

Figure 3.1 SMBus Timing Diagram

Table 3.1 Protocol Format

DATA SENT

TO DEVICE

DATA SENT TO

THE HOST

Table 3.2 Write Byte Protocol

START

SLAVE

ADDRESS

ACK

ADDRESS

ACK

DATA

ACK

STOP

1 -> 0

1001_100

XXh

0 -> 1

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