EMC6D103S-CZC SMSC, EMC6D103S-CZC Datasheet - Page 18

• Manufacturer Part Number: EMC6D103S-CZC
• Description: Industrial Temperature Sensors Auto Fan Contrllr Up to 4 Fans
• Manufacturer: SMSC

Specifications of EMC6D103S-CZC

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Revision 0.3 (03-01-07)
5.2
5.3
SDA
SCL
Slave Bus Interface
Bus Protocols
Start
The EMC6D103 device SMBus implementation is a subset of the SMBus interface to the host. The
device is a slave-only SMBus device. The implementation in the device is a subset of SMBus since it
only supports Write Byte and Read Byte protocols.
The Write Byte and Read Byte protocols are valid SMBus protocols for the device. This part responds
to other protocols as described in the Invalid Protocol Section. Reference the System Management
Bus Specification, Rev 2.0.
The SMBus interface is used to read and write the registers in the device. The register set is shown
in section 11 Register Set on page 31.
Typical Write Byte and Read Byte protocols are shown below. Register accesses are performed using
7-bit slave addressing, an 8-bit register address field, and an 8-bit data field. The shading indicates
the Hardware Monitor Block driving data on the SDA line; otherwise, host data is on the SDA line.
The slave address is the unique SMBus Interface Address for the Hardware Monitor Block that
identifies it on SMBus. The register address field is the internal address of the register to be accessed.
The register data field is the data that the host is attempting to write to the register or the contents of
the register that the host is attempting to read.
Note: Data bytes are transferred MSB first.
Byte Protocols
A write byte transfer will always consist of the SMBus Interface Address byte, followed by the Internal
Address Register byte, then the data byte. There are two cases for a read:
1. The normal read protocol consists of a write to the Hardware Monitor Block with the SMBus
2. If the Internal Address Register is known to be at the desired Address, simply read the Hardware
Interface Address byte, followed by the Internal Address Register byte. Then restart the Serial
Communication with a Read consisting of the SMBus Interface Address byte, followed by the data
byte read from the Hardware Monitor Block. This can be accomplished by using the Read Byte
protocol or by using the Send Byte protocol followed by the Receive Byte protocol.
Monitor Block with the SMBus Interface Address byte, followed by the data byte read from the
Hardware Monitor Block. This corresponds to the Receive Byte protocol.
0
Figure 5.1 Address Selection on EMC6D103
1
Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
First five address bits
0
DATASHEET
18
1
1
Address Decided
SMSC EMC6D103
Datasheet