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Altera_Forum's avatar
Altera_Forum
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20 years ago

Nios II EDS v6.0 Released- Download Now

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Also included in the 6.0 release is hardware support for floating point operations, implemented as a library of custom instructions.[/b]

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Anybody played with floating point as a library of custom instructions ?

I have not purchased NiosII 6 yet, still use 5.0 and I am interested in how much LE these special instructions for floating point take...

Let&#39;s say I am using the smallest, economy version of NiosII core - how much increase in size I can expect when I use hardware floating point as library of custom instructions ?

Also, will they completely replace the need for the emulation library ? Are they giving full hardware support to floating point similar to a math coprocessor found on x86 machines ?

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Hello Pszemol,

    For your first question, regarding device resource utilization, see the following document:

    using nios ii floating point custom instructions tutorial (http://www.altera.com/literature/tt/tt_floating_point_custom_instructions.pdf)

    To your second question: no, the custom instruction library will not replace every emulated software function. The custom instructions implement in hardware the basic floating point math functions: add, substract, multiply, and divide (optional). Any functions that use these basic math routines will indirectly use the custom instruction hardware. For instance, the cosine routine will use the multiplication math hardware that is implemented as a custom instruction.

    I hope this is all clear, but feel free to post any other questions.