DSP

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Revision as of 18:10, 23 July 2018 by JayFoxRox (talk | contribs) (I've measured memory sizes of the Xbox DSPs using a program)
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The DSPs in the APU are probably "Parthus MediaStream" DSP core (DSP24210/DSP2420?).

Those are similar to Motorola DSP56362 (DSP56300 Family). If so, the datasheet can be found at http://www.nxp.com/docs/en/data-sheet/DSP56362.pdf (Also see "Documentation" section in said datasheet for the related documentation)

Memory Size

Program RAM Size X Data RAM Size Y Data RAM Size
GP 4096[FIXME] x 24-bit 4096 x 24-bit 2048 x 24-bit
EP 4096[FIXME] x 24-bit 3072 x 24-bit 256 x 24-bit

Other datasheets for similar DSPs suggest that the memory sizes might be different if instruction cache or switch mode are toggled. It is currently unknown if the DSPs in the Xbox APU support a similar feature[FIXME].

DMA

This section is very incomplete and not much was tested on hardware either

Sample formats:

  • 0x0 = 8 bit
  • 0x1 = 16 bit
  • 0x2 = 24 bit in MSB
  • 0x3 = 32 bit
  • 0x4
  • 0x5
  • 0x6 = 24 bit in LSB (also endianess switched?[citation needed])
  • 0x7

Buffers:

Related links