82801E datasheet(78/84 Pages) INTEL

78 / 84 page

Intel® 82801E C-ICH

Advance Information Datasheet

5.2

Tri-state Mode

When in the tri-state mode, all outputs and bidirectional pin are tri-stated, including the XOR

Chain outputs.

5.3

XOR Chain Mode

In the 82801E C-ICH, provisions for Automated Test Equipment (ATE) board level testing are

implemented with XOR Chains. The 82801E C-ICH signals are grouped into four independent

XOR chains which are enabled individually. When an XOR chain is enabled, all output and

bidirectional buffers within that chain are tri-stated, except for the XOR chain output. Every signal

in the enabled XOR chain (except for the XOR chain’s output) functions as an input. All output and

bidirectional buffers for pins not in the selected XOR chain are tri-stated. Figure 30 is a schematic

example of XOR chain circuitry.

Table 57 - Table 60 list each XOR chain pin ordering, with the first value being the first input and

the last value being the XOR chain output. Table 61 lists the signal pins not included in any XOR

chain.

Figure 30. Example XOR Chain Circuitry

Input

Pin 2

Vcc

Input

Pin 1

Input

Pin 3

Input

Pin 4

Input

Pin 5

Input

Pin 6

XOR

Chain

Output

82801E Datasheet(PDF) 78 Page - Intel Corporation