Intel C2518 FH8065501516710 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

Datasheet, Vol. 2 of 3

September 2014

296

Order Number: 330061-002US

 identifies the hardware pattern-matching which is required to decode ARP 

and ordinary SMBus protocols. The UDID matching applies only to Assign Address 

protocol.

Since ARP protocols are typically writes to the ARP slave by the ARP host, the R/W# bit 

(LSB) of the first byte is usually 0; however, the general and directed forms of Get 

UDID require the ARP slave to return its UDID to the ARP host, such that the LSB of the 

first byte after the repeated-start is 1. During either Get UDID protocol, the hardware 

matching must detect the repeated-start and subsequently match a slave address of 

C3h.

Likewise, most ordinary SMBus protocols begin with a write to the slave/target by the 

master. However, since certain protocols begin with a read to the slave, the hardware 

matching treats the LSB of the first byte as a (don’t care). For those protocols which 

require the slave to return data to the master, the LSB of the first byte after the 

repeated-start is 1. Therefore, the hardware matching must detect the repeated-start 

and subsequently match a slave address with an appended 1 LSB.

26.

Is this a directed Reset Device command? If so then proceed to step 15. 

Otherwise proceed to step 27.

• [FW] Inspects command field and 

determines how to proceed

27.

Is this the Get UDID (directed) command? If so then proceed to step 

29. Return the UDID information. If not, then proceed to step 28.

• [HW] Inspects command field and 

determines how to proceed

28.

The device has not received a valid command so it must handle the 

illegal command in accordance with SMBus rules for error handling. 

Proceed to step 7 and wait for another SMBus packet.

• [FW] Perform error handling

29.

Return the UDID information and current slave address, then proceed 

to step 7 and wait for another SMBus packet.

• [HW] UDID and current slave address are 

returned as read data to master (as per 

generic block-read payload)

1. FW means Firmware.

2. HW means Hardware.