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Altera_Forum
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12 years ago

De2-115 windows application to control Cyclone chip

Hi, I bought Altera board (development) DE2-115 In the example CD - there is a very nice PC application with UI - when pressing buttons-> altera board light leds, show LCD when you write in PC e...
Altera_Forum's avatar
Altera_Forum
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12 years ago

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Something I misunderstand,

If I am using JTAG debugger (in Programmer),

I can move bits to JTAG and make CLOCKS and see TDO as I expect,

But when I see TDO=1 => I don't see my green led on board lighting? why is that am I missing something?

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It does not work because you have not read any of the documentation and understood how the JTAG component works.

The TDO from the SLD_Virtual_JTAG component is *NOT* the same as the external pin. There is multiplexing logic in the SLD_Virtual_JTAG component. You need to issue JTAG commands to select your component first. The vjtag.pdf document contains example Tcl code and SignalTap II logic analyzer traces. Add a SignalTap II instance to your design and you will see that TDO will not change until you issue the correct commands.

Cheers,

Dave