User Manual

VS1003

8 FUNCTIONAL DESCRIPTION

8.6.1 SCI_MODE (RW)

SCI_MODE is used to control the operation of VS1003 and defaults to 0x0800 (SM_SDINEW

set).

Bit Name Function Value Description

0 SM_DIFF Differential 0 normal in-phase audio

1 left channel inverted

1 SM_SETTOZERO Set to zero 0 right

1 wrong

2 SM_RESET Soft reset 0 no reset

1 reset

3 SM_OUTOFWAV Jump out of WAV decoding 0 no

1 yes

4 SM_PDOWN Powerdown 0 power on

1 powerdown

5 SM_TESTS Allow SDI tests 0 not allowed

1 allowed

6 SM_STREAM Stream mode 0 no

1 yes

7 SM_SETTOZERO2 Set to zero 0 right

1 wrong

8 SM_DACT DCLK active edge 0 rising

1 falling

9 SM_SDIORD SDI bit order 0 MSb ﬁrst

1 MSb last

10 SM_SDISHARE Share SPI chip select 0 no

1 yes

11 SM_SDINEW VS1002 native SPI modes 0 no

1 yes

12 SM_ADPCM ADPCM recording active 0 no

1 yes

13 SM_ADPCM_HP ADPCM high-pass ﬁlter active 0 no

1 yes

14 SM_LINE_IN ADPCM recording selector 0 microphone

1 line in

When SM_DIFF is set, the player inverts the left channel output. For a stereo input this creates

virtual surround, and for a mono input this creates a differential left/right signal.

Software reset is initiated by setting SM_RESET to 1. This bit is cleared automatically.

If you want to stop decoding a WAV, WMA, or MIDI ﬁle in the middle, set SM_OUTOFWAV, and

send data honouring DREQ until SM_OUTOFWAV is cleared. SCI_HDAT1 will also be cleared.

For WMA and MIDI it is safest to continue sending the stream, send zeroes for WAV.

Bit SM_PDOWN sets VS1003 into software powerdown mode. Note that software powerdown

is not nearly as power efﬁcient as hardware powerdown activated with the XRESET pin.

If SM_TESTS is set, SDI tests are allowed. For more details on SDI tests, look at Chapter 9.8.

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