Intel Xeon Wolfdale E3210 P4X-UPE3210-316-6M1333 Data Sheet

Datasheet

315

In the MCH, testability for Automated Test Equipment (ATE) board level testing has 

been implemented as an XOR chain. An XOR-tree is a chain of XOR gates each with one 

input pin connected to it which allows for pad to ball to trace connection testing.

The XOR testing methodology is to boot the part using straps to enter XOR mode (A 

description of the boot process follows). Once in XOR mode, all of the pins of an XOR 

chain are driven to logic 1. This action will force the output of that XOR chain to either 

a 1 if the number of the pins making up the chain is even or a 0 if the number of the 

pins making up the chain is odd.

Once a valid output is detected on the XOR chain output, a walking 0 pattern is moved 

from one end of the chain to the other. Every time the walking 0 is applied to a pin on 

the chain, the output will toggle. If the output does not toggle, there is a disconnect 

somewhere between die, package, and board and the system can be considered a 

failure. 

XOR inputs

XOR output

X