Texas Instruments TMS320C64X User Manual
Page 73
DSP_fir_gen_hM17_rA8X8
4-45
C64x+ DSPLIB Reference
Special Requirements
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The number of coefficients, nh, must be greater than or equal to 17.
Coefficients must be in reverse order.
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The number of outputs computed, nr, must be a multiple of 8 and greater
than or equal to 8.
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Array r[ ] must be word aligned.
Implementation Notes
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Bank Conflicts: No bank conflicts occur.
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Interruptibility: The code is fully interruptible.
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Load double-word instruction is used to simultaneously load four values
in a single clock cycle.
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The inner loop is unrolled four times and will always compute a multiple
of 4 of nh and nr. If nh is not a multiple of 4, the code will fill in zeros to make
nh a multiple of 4.
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This code yields best performance when the ratio of outer loop to inner
loop is less than or equal to 4.
Benchmarks
Cycles: 3*ceil(nh/4)*nr/4+39
Codesize: 416 bytes