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SH3-DSP Registers

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SH3-DSP extends the capabilities of the SH-3 microprocessor, and adds registers that permit digital signal processing. Use volatile and nonvolatile registers for DSP instructions in the same way that the SH-3 Calling Sequence Specification defines register use.

If the calling function uses volatile registers, then calling function should save these before a subroutine call. The following list shows the volatile registers that the calling function should save:

  • As2 (R2)
  • As3 (R3)
  • As0/Ax0 (R4)
  • As1/Ax1 (R5)
  • Ay0 (R6)
  • Ay1 (R7))

The called function saves each non-volatile register that has a DSP alias. The following list shows the non-volatile registers:

  • Is/Ix (R8)
  • Iy (R9)

See Also

SH-3 Calling Sequence Specification | SH3-DSP Calling Sequence Specifications | SH3-DSP Documentation Disclaimer | SH3-DSP Data Formats | SH3-DSP Instructions | SH3-DSP General Registers | SH3-DSP Status Registers | SH3-DSP Control Registers | RS, RE, and ME Control Registers | SH3-DSP System Registers | DSP Unit Registers

 Last updated on Thursday, April 08, 2004

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