Intel 82555 manual Test Instruction Coding, Number Code Test Instruction Select Input to Tout

Models: 82555

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82555 — Networking Silicon

The TOUT pin is controlled by different sources according to the active test instruction. The TOUT signal is activated by the falling edge of TCK. The TAP must be reset during power-up. Otherwise, the 82555 can wake-up during high-Z mode or NAND Test, which can be harmful to the board.

The TAP should be reset only with a hardware reset input pin and not with software reset. The TOUT control logic selects the TISR output in all tests, except burn-in test modes.

Table 6. Test Instruction Coding

Number

Code

Test Instruction

Select Input to TOUT

 

 

 

 

 

 

 

 

1

00000

Idle

TISR D4out

 

 

 

 

2

00001

Reserved

TISR D4out

 

 

 

 

3

00010

High-Z

High-Z

 

 

 

 

4

00011

NAND Test

TISR D4out

 

 

 

 

42

Datasheet

Page 46
Image 46
Intel 82555 manual Test Instruction Coding, Number Code Test Instruction Select Input to Tout