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Altera_Forum's avatar
Altera_Forum
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18 years ago

Tri-state output and OpenDrain-output in FLEX 10KA

Hi All,

I don't undestand in FLEX 10KA. How does "Individual tri-state output enable control for each pin" work. How I can select between Tri-state output and OpenDrain output with IDE MAX+plus II. Where I can read about this?

Thanks.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    You implement an opendrain ouput by using a Tristate output.:

    Pin = tri.out;

    tri.in = gnd;

    tri.ena = data;

    You can find the tri primitive ( AHDL ) in maxplus II at:

    help->primitives

    succes,

    Andries
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Hi, Andries! Thanks for answer.

    I am reprogramming now the old project on the chip FLEX 10K30A and wont to use Verilog HDL. The FPGA connects to RAM with the tri-state buses in 32-bits. When I implement the primitive TRI(in, oe, out), FPGA forms only 0,z states (It was open drain, I think). And all was OK with 0,1,z states when I implemented graphic primitive TRI from library c:\maxplus2\max2lib\prim in the graphic’s mode (It was full tri-states output, I think). In both cases I used TRI primitive. Why does it occur? Why I can’t work with tri-state buses in Verilog HDL and can only in *.gdf? What is wrong?

    Best regards,

    Serhiy.