AR# 13018

4.1is3 ECS - How do I use the TDO pin for regular I/O in 4K(XL)/Spartan(-XL) chips?

Description

Keywords: TDO, BSCAN, Spartan, schematic, symbol, ECS

Urgency: Standard

General Description:
I would like to use the TDO pin of my device as a regular I/O. How do I do this?

Solution

1

A TDO symbol does not currently exist in ECS. Therefore, you must create a symbol by instantiating the TDO in HDL and generating a symbol for it under "Design Entry Utilities". (Instantiations can be found in Resolutions 2 and 3.)

This issue is fixed in the latest 4.2i service pack, available at:
http://support.xilinx.com/support/techsup/sw_updates
The first service pack containing the fix is 4.2i Service Pack 2.

2

VHDL Instantiation of TDO:

component TDO
port(
O : in STD_ULOGIC);
end component;

3

Verilog Instantiation of TDO:

module TDO(O);
input O;
endmodule

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AR# 13018
Date	08/11/2003
Status	Archive
Type	General Article

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