Intel C2518 FH8065501516710 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

September 2014

Datasheet, Vol. 2 of 3

Order Number: 330061-002US

291

The following are some definitions pertaining to SMBus ARP.

Address Resolution Protocol (ARP)

A protocol by which SMBus devices with assignable addresses on the bus 

are enumerated and assigned non-conflicting slave addresses.

Address Resolved (AR) flag

A flag bit or state internal to the SoC that indicates whether or not the 

device slave address has been resolved by the ARP Master.

Address Valid (AV) flag

A flag bit or state internal to SoC that indicates whether or not the 

device slave address is valid. This bit must be non-volatile for devices 

that support the Persistent Slave Address.

ARP Master

The SMBus master executes the ARP and assigning addresses to ARP-

capable slave devices. The SMBus Host usually is the ARP Master, but 

under some circumstances another SMBus master assumes the role. 

Only one active ARP Master exists at any time.

Persistent Slave Address (PSA)

An assigned slave address that is retained through the loss of device 

power.

SMBus Device Default Address

The address all ARP-capable slave device must respond to. After a slave 

address has been assigned a device must still respond to commands at 

the SMBus Device Default Address for ARP management. This address is 

fixed at 1100 001.

SMBus Host

A specialized SMBus Master that provides the main interface to the 

system CPU. It must be a master-slave and must support the SMBus 

host notify protocol. At most, one host is in a system.

Unique Device Identifier (UDID)

A 128-bit value that a device uses during the ARP process to uniquely 

identify itself.

Cleared

Cleared

The device does not have a valid slave address and participates in 

the ARP process. This is the POR state for a device that does not 

support the PSA (persistent slave address) or if it does it has not 

previously been assigned a slave address.

Cleared

Set

ILLEGAL STATE

Set

Cleared

The device has a valid slave address but must still participate in the 

ARP process.

Set

Set

The device has a valid slave address that has been resolved by the 

ARP Master. The device does not respond to the Get UDID (general) 

command. However, it subsequently receives an Assign Address 

command and changed its slave address accordingly.