6402 datasheet(21/250 Pages) INTEL

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Intel® 6400/6402 Advanced Memory Buffer Datasheet

FBD Channel Interface

2.6

Repeater Mode

The AMB may also be used as an FBD link repeater to extend distances at which links

can operate. This mode can be automatically set by the BFUNC and SA pins. In this

mode, the AMB functions in the same way as a regular DIMM with the exception that

DRAM commands are not supported.

Link behavior is the same as for normal DIMMs

• Participates in link initialization like a normal DIMM

• Responds to Reads and Writes to AMB configuration registers

• Status is returned in response to Sync commands

• Link errors are detected and alerts generated

SMBus access is the same except for the base Slave address is different than from

normal DIMM.

Slave address[6:3] = 4’b0011 for Repeaters, instead of

Slave address[6:3] == 4’b1011 for normal DIMMs

2.7

Channel Latency

The critical elements that AMB contributes to the latency calculation are the chip

crossing delays.

• Southbound latency contributions

— Delay from an input FBD link transaction to commands on the DDR interface

and

— Pass-thru delay of forwarded Southbound FBD transactions.

• Northbound latency contributions

— Delay from DDR Read data input on the last DIMM to FBD link transactions and

— Pass-thru delay of forwarded Northbound FBD transactions back towards the

host.

These timing delay values are documented in Chapter 4, “Electrical, Power, and

Thermal.”

2.7.1

Command to Data Delay Calculation

shows the various components that make up the over all delay through an AMB for a

memory command.

6402 Scheda tecnica(PDF) 21 Page - Intel Corporation