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DSPLIB 中FFT接口使用问题

bo tang
Genius 3096 points


1 在C6748上测试dsplib_c674x_3_4_0_0中FFT时间，

   在DSPLIB_C674x_TestReport.html中查看到DSPF_sp_fftSPxSP接口对应测试结果是：

DSPF_sp_fftSPxSP Passed 1069 (N=128) 1965 (N=256) N/A 928
Test Parameters
Precision:Fixed Point
Endianness:Little
Object File Format:COFF
Platform:CCS Simulator
Cores Used:1
CCS Version:5.4.0.00091
CGT Version:7.4.2

我在板上实际测试时需要什么条件下才能达到这个cycle数？256点情况下；

2 在DSPF_sp_fftSPXSP的说明中有如下一段，请问是什么意思？

Interruptibility: The code is interrupt-tolerant but not interruptible.  

  • 0
    Genius 3096 points

    我这边测试O3优化 release版本，DSPF_sp_fftSPXSP输入数据全部在L1D中，跑出来要3089个cycle。

    和报告差异太大

  • 0 回复 bo tang
    TI__Guru**** 357097 points

    dsplib结果是在ccs simulator测试的，simulator软仿真不能准确地反映memory访问、cache miss、及内部总线冲突等引入的时延，与仿真器结果有差异。

    "interrupt-tolerant"  means you do not have to turn off interrupts before calling these functions. If a section of the function needs to prevent interrupts for a period of time, that will be handled by the function itself.

    "not interruptible "means portions of the function may prevent interrupts during tightly optimized loops for performance reasons. During this time, interrupt latency will be increased but the interrupts will occur once that portion of the code has completed.

     

  • 0 回复 Shine
    Genius 3096 points

    问一下下面两个解释的出处：

    "interrupt-tolerant"  means you do not have to turn off interrupts before calling these functions. If a section of the function needs to prevent interrupts for a period of time, that will be handled by the function itself.

    "not interruptible "means portions of the function may prevent interrupts during tightly optimized loops for performance reasons. During this time, interrupt latency will be increased but the interrupts will occur once that portion of the code has completed.

  • 0 回复 Shine
    Genius 3096 points

    dsplib结果又在板上实测的结果报告吗？

  • 0 回复 bo tang
    TI__Guru**** 357097 points

    countryhotel 说：

    问一下下面两个解释的出处：

    "interrupt-tolerant"  means you do not have to turn off interrupts before calling these functions. If a section of the function needs to prevent interrupts for a period of time, that will be handled by the function itself.

    "not interruptible "means portions of the function may prevent interrupts during tightly optimized loops for performance reasons. During this time, interrupt latency will be increased but the interrupts will occur once that portion of the code has completed.



    来自下面的帖子。
    https://e2e.ti.com/support/dsp/tms320c6000_high_performance_dsps/f/115/t/180275 

  • 0 回复 bo tang
    TI__Guru**** 357097 points

    countryhotel 说：

    dsplib结果又在板上实测的结果报告吗？

    没有。