Intel C2518 FH8065501516710 Data Sheet

Intel

Product codes

FH8065501516710

Volume 2—SMBus 2.0 Unit 0 - PCU—C2000 Product Family

System Host Controller

Intel

®

Atom™ Processor C2000 Product Family for Microserver

Datasheet, Vol. 2 of 3

September 2014

432

Order Number: 330061-002US

18.3.1.2

Send Byte/Receive Byte Command

For the Send Byte command, the Transmit Slave Address (SMB_Mem_TSA) and Host

Command (SMB_Mem_HCMD) registers are sent. For the Receive Byte command, the

Transmit Slave Address (SMB_Mem_TSA) register is sent. The data received is stored in

the Data 0 (SMB_Mem_HD0) register. The software must force the

SMB_Config_HCFG.I2C_EN bit to 0b when running this command.

The Receive Byte is similar to a Send Byte, the only difference is the direction of data

transfer. See Sections 5.5.2 and 5.5.3 of the System Management Bus (SMBus)

Specification, Version 2.0 for the format of the protocol.

18.3.1.3

Write Byte/Word Command

The first byte of a Write Byte/Word access is the command code. The next 1 or 2 bytes

are the data to be written. When programmed for a Write Byte/Word command, the

Transmit Slave Address (SMB_Mem_TSA), Host Command (SMB_Mem_HCMD), and

Data 0 (SMB_Mem_HD0) registers are sent. In addition, the Data 1 (SMB_Mem_HD1)

register is sent on a Write Word command. The software must force the

SMB_Config_HCFG.I2C_EN bit to 0 when running this command. See Section 5.5.4 of

the System Management Bus (SMBus) Specification, Version 2.0 for the format of the

18.3.1.4

Read Byte/Word Command

Reading data is slightly more complicated than writing data. First the SoC must write a

command to the slave device. Then it must follow that command with a repeated start

condition to denote a read from that device address. The slave then returns 1 or 2

bytes of data. The software must force the SMB_Config_HCFG.I2C_EN bit to 0b when

running this command.

When programmed for the Read Byte/Word command, the Transmit Slave Address

(SMB_Mem_TSA) and Host Command (SMB_Mem_HCMD) registers are sent. Data is

received into the Data 0 (SMB_Mem_HD0) on the read byte, and the Data 0

(SMB_Mem_HD0) and Data 1 (SMB_Mem_HD1) registers on the read word. See

Section 5.5.5 of the System Management Bus (SMBus) Specification, Version 2.0 for

the format of the protocol.