Re: Optimizing a tapped delay (FIR) filter implementation

Kumar Appaiah wrote:

It looks like there is some jinx! Moments after I post a query on
comp.dsp, I get the answer:

http://www.dspguru.com/info/faqs/fir/implemnt.htm

However, in the document, the idea proposed is doubling the length of
one of the FIR data lines, and duplicating the buffer contents, so that
the overflow is taken care of. Though this is very efficient when it
comes to cycles, it eats huge memory. I was wondering whether there was
a way to have the cake and eat it too, by striking a balance somewhere
in between.

Or, if you feel about 20 kilo bytes of memory duplicated is all right
(this is for a PC, not a DSP), please tell me.

Thanks.

Kumar

Same effect can be achieved by taking advantage of the mmu. Many OSs allow
you to map two pages to same physical address. In the sense of used
physical memory, this is free.

--
Jani Huhtanen
Tampere University of Technology, Pori
.

Relevant Pages

  • Re: Optimizing a tapped delay (FIR) filter implementation
    ... However, in the document, the idea proposed is doubling the length of ... one of the FIR data lines, and duplicating the buffer contents, so that ... comes to cycles, it eats huge memory. ... if you feel about 20 kilo bytes of memory duplicated is all right ...
    (comp.dsp)
  • relic Have you learned how to post yet?
    ... As you have a selective memory, here is the source code for you. ... applications with a 4 GB virtual address space. ... that run on computers with more than 2 GB of physical memory. ... Address Windowing Extensions (AWE) enables applications to address more = ...
    (alt.os.windows-xp)
  • Re: RAM
    ... For applications that are I/O-intensive, ... The 4GT RAM Tuning feature increases the memory ... more than 2 GB of physical memory. ... VirtualAlloc function. ...
    (alt.os.windows-xp)
  • Re: 4GB Physical Memory Support
    ... Whether or not 4GB of physical memory is necessary is a moot point, the question remains why changing the page file size altered the amount of physical memory recognized by Windows. ... However, keep in mind that the PCI Hole exists as a result of addressing done by the BIOS, not by Windows. ...
    (microsoft.public.windowsxp.hardware)
  • Re: OS-question
    ... MacOS X supports>4GB of RAM on IA32 and so does FreeBSD but I don't know ... Linux can use up to 64 Gigabytes of physical memory on x86 systems. ... If you are compiling a kernel which will never run on a machine with ...
    (comp.arch)