Intel C2518 FH8065501516710 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

September 2014

Datasheet, Vol. 2 of 3

Order Number: 330061-002US

295

15.

Upon receipt of the Reset Device command the device must 

acknowledge the packet and make sure its Address Valid (if non-PSA) 

and Address Resolved flags are cleared. This allows the ARP Master to 

re-assign all device addresses without cycling power. Proceed to step 7 

and wait for another SMBus packet.

• [FW] Deassert SMTARPCTRL.AV* 
• [FW] Deassert SMTARPCTRL.AR* 

16.

The device checks the command field to verify if the Assign Address 

command was issued. If so, then it proceeds to step 17, otherwise it 

proceeds to step 19.

• [FW] Inspects command field and 

determines how to proceed

17.

Upon receipt of the Assign Address command the device must compare 

its UDID to the one it is receiving. If any byte does not match then it 

must not acknowledge that byte or subsequent ones. If all bytes in the 

UDID compare then the device proceeds to step 18, otherwise it must 

return to step 7 and wait for another SMBus packet.

• [HW] Check command field only if 

received slave address matches Device 

Default Address

• [HW] If the Assign Address command, 

then verify each byte of received UDID 

against all SMT UDIDs.

• [HW] NACK the transaction if received 

UDID fails to match any SMT UDID

All ARP protocols are directed only to 

the Device Default Address.

SMT must respond to this command 

even if its SMTARPCTRL.AR flag is set 

(i.e., ARP Master overwrites a valid 

and resolved target address).

This also implies the hardware 

cannot detect an ARP-pending flag to 

selectively monitor the command 

field for Assign Address command.

If UDID is NACKed, the hardware is 

not required to notify the firmware.

18.

Since the UDID matched, the device must assume the received slave 

address and update its PSA, if supported. The device must set its 

Address Valid and Address Resolved flags; this indicates it no longer 

responds to the Get UDID command unless it receives the Prepare To 

ARP or Reset Device commands or is power cycled. Proceed to step 7 

and wait for another SMBus packet.

• [FW] Assign the received slave address to 

the matched UDID

• [FW] Assert SMTARPCTRL.AVn 
• [FW] Assert SMTARPCTRL.ARn 

19.

The device checks the command field to verify if the Get UDID 

command was issued. If so, then it proceeds to step 21, otherwise it 

proceeds to step 20.

• [HW] Inspects command field and 

determines how to proceed

20.

The device is receiving a directed command. Directed commands must 

be acknowledged only by slaves with a valid address. If the address is 

not valid then ignore the packet and return to step 7 and wait for 

another SMBus packet. If the address is valid then proceed to step 26.

• [HW] Inspects Address Valid flag

21.

Upon receipt of the Get UDID command, the device must check its 

Address Resolved flag to determine whether or not it participates in the 

ARP process. If set then its address has already been resolved by the 

ARP Master so the device proceeds to step 7 to wait for another SMBus 

packet. If the AR flag is cleared then the device proceeds to step 22.

• [HW] Inspects Address Resolved flag and 

determines how to proceed

22.

The device returns its UDID and monitors the SMBus data line for 

collisions. If a collision is detected at any time the device must stop 

transmitting and proceed to step 7 and wait for another SMBus packet. 

If no collisions were detected then proceed to step 23.

• [HW] UDID is returned as read data to 

master

23.

The device must now check its Address Valid flag to determine what 

value to return for the Device Slave Address field. If the AV flag is set 

then it proceeds to step 24, otherwise it proceeds to step 25.

• [HW] Inspects Address Valid flag and 

determines how to proceed

24.

The current slave address is valid so the device returns this for the 

Device Slave Address field (with bit 0 set) and monitors the SMBus data 

line for collisions (i.e., another device driving a 0 when this device is 

driving a 1). 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)

25.

The current slave address is invalid so the device returns a value of 

0xFF and monitors the SMBus data line for collisions. If the ARP Master 

receives the 0xFF value it knows that the device requires address 

assignment. Proceed to step 7 and wait for another SMBus packet.

• [HW] UDID and 0xFF address are 

returned as read data to master (as per 

generic block-read payload)