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Altera_Forum
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16 years ago

FFT C2H tutorial Not Working

Hi All,

I have a specific case where in the tutorial doesnt work. Does anyone have a clue what could have gone wrong and how to rectify it .

Error Log :

FFT Benchmark Starting (this will take up to 20 seconds)

- Running 1000 iterations for both software and hardware.

- Each iteration runs a 256 point radix 2 FFT transformation.

Accelerated FFT is incorrect

Error at index 0, received 52 0i, expected -244 0i

--Performance Counter Report--

Total Time: 6.67832 seconds (333915759 clock-cycles)

+---------------+-----+-----------+---------------+-----------+

| Section | % | Time (sec)| Time (clocks)|Occurrences|

+---------------+-----+-----------+---------------+-----------+

|Software Only | 93.9| 6.27272| 313636207| 1|

+---------------+-----+-----------+---------------+-----------+

|HW Accelerated | 6.04| 0.40352| 20175989| 1|

+---------------+-----+-----------+---------------+-----------+

The software only output data is correct

Definitions :

# define BufferRAM1 (alt_16 *)0x2000# define BufferRAM2 (alt_16 *)0x4000# define BufferRAM3 (alt_16 *)0x6000# define BufferRAM4 (alt_16 *)0x8000# define BufferRAM5 (alt_16 *)0x3000# define BufferRAM6 (alt_16 *)0x5000# define CosRAM (alt_16 *)0xA000# define SinRAM (alt_16 *)0xB000

I am attaching the ScreenShot of my SOPC builder.

Hopefully someone could take a look at this one and let me know the details.

Cheers,

Ittiam

1 Reply

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

    For the accelerator optimized FFT, I get the result as below: -

    nios2-terminal: connected to hardware target using JTAG UART on cable

    nios2-terminal: "USB-Blaster [USB-0]", device 1, instance 0

    nios2-terminal: (Use the IDE stop button or Ctrl-C to terminate)

    FFT Benchmark Starting (this will take up to 20 seconds)

    - Running 1000 iterations for both software and hardware.

    - Each iteration runs a 256 point radix 2 FFT transformation.

    --Performance Counter Report--

    Total Time: 2.18095 seconds (290792861 clock-cycles)

    +---------------+-----+-----------+---------------+-----------+

    | Section | % | Time (sec)| Time (clocks)|Occurrences|

    +---------------+-----+-----------+---------------+-----------+

    |Software Only | 98| 2.13722| 284962337| 1|

    +---------------+-----+-----------+---------------+-----------+

    |HW Accelerated | 1.99| 0.04344| 5792204| 1|

    +---------------+-----+-----------+---------------+-----------+

    The software only output data is correct

    The hardware accelerated output data is correct

    nios2-terminal: exiting due to ^D on remote

    you may clean the project and rebuild again.

    By the way, the definitions for the accelerator optimized FFT I build is as below: -

    #define BufferRAM1 (alt_16 *)0x0000

    #define BufferRAM2 (alt_16 *)0x0200

    #define BufferRAM3 (alt_16 *)0x0400

    #define BufferRAM4 (alt_16 *)0x0600

    #define CosRAM (alt_16 *)0x0800

    #define SinRAM (alt_16 *)0x0A00

    Regards,

    syleow