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RRU SPT issues

Question asked by Moez Selmi Employee on Jul 19, 2019
Latest reply on Jul 22, 2019 by Moez Selmi

The result are different between the NXP simulator and the embedded system

 

Here are the two results for the first FFT16 with windowing:

 

From simulator:

 

0xa000; 0xfff31c +i 0x000dd6

0xa001; 0x0000af +i 0x0025f7

0xa002; 0x002316 +i 0x0020b1

0xa003; 0x0027a0 +i 0x0000a7

0xa004; 0x000ff9 +i 0xfff8c1

0xa005; 0x0008dc +i 0x000afa

0xa006; 0x0019a6 +i 0x0014a6

0xa007; 0x002b2e +i 0x000751

0xa008; 0x002688 +i 0xffeed4

0xa009; 0x000de9 +i 0xffeabf

0xa00a; 0x000880 +i 0xffff30

0xa00b; 0x001c5d +i 0xfffed0

0xa00c; 0x0017b7 +i 0xffe55d

0xa00d; 0xfffa10 +i 0xffe634

0xa00e; 0xfff364 +i 0xfffd30

0xa00f; 0xfff948 +i 0x0003d1

 

 

 

From embedded system:

 

0xa000; 0xfff31c +i 0x000dd6

0xa001; 0xfff948 +i 0x0003d1

0xa002; 0xfff364 +i 0xfffd30

0xa003; 0xfffa10 +i 0xffe634

0xa004; 0x0017b7 +i 0xffe55d

0xa005; 0x001c5d +i 0xfffed0

0xa006; 0x000880 +i 0xffff30

0xa007; 0x000de9 +i 0xffeabf

0xa008; 0x002688 +i 0xffeed4

0xa009; 0x002b2e +i 0x000751

0xa00a; 0x0019a6 +i 0x0014a6

0xa00b; 0x0008dc +i 0x000afa

0xa00c; 0x000ff9 +i 0xfff8c1

0xa00d; 0x0027a0 +i 0x0000a7

0xa00e; 0x002316 +i 0x0020b1

0xa00f; 0x0000af +i 0x0025f7

 

As you can see, the results are globally the same one but the order of the data is not the same in the memory.

For example, the data at address 0xa001 in the simulator is at the address 0xa00f in the embedded system. And so on…

 

This example computes a FFT16 of complexes in rounded mode(256 * FFT16).

The input data is at addresses 0xA000-0xAFFF in OPRAM, and the result is also at the addresses 0xA000 – 0xAFFF

With the SPT tools box in Matlab, we have a similar result as the NXP simulator.

 

Do you aware of this behavior?

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