Re: JTAG/Boundary Scan

["Andy Ingraham" <ingraham@wrksys.ENET.dec.com>]

> Section 2.2.10 of the spec. says the following:
>
> Expansion boards that do not support the IEEE 1149.1 interface should
> hardwire the board's TDI pin to its TDO pin.

> Section 4.3.3 says the following:
> ..if boundary scan is not implemented on the planar, TMS and TDI 
> should be independently bused and pulled up each with ~5Kohm 
> resistors, and TRST# and TCK should be independently bused 
> and pulled down, each with ~5K ohm resistors. TDO should be left open.

Section 4.3.3 is for motherboards.  All of Section 4.3.* is for
motherboards.  4.4.* is for plug-in cards.

Also see 4.4.1, which applies to expansion boards, and says, "Boards
that do not implement JTAG Boundary Scan are required to connect TDI and
TDO (pins 4a and 4b) so the scan chain is not broken."

Regards,
Andy Ingraham


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