VS1011 Datasheet, PDF (26/43 Pages) List of Unclassifed Manufacturers – MP3 AUDIO CODEC

VLSI
Solution ^y
VS1011 PRELIMINARY
VS1011
8. FUNCTIONAL DESCRIPTION
SM STREAM activates VS1011’s stream mode. In this mode, data should be sent with as even intervals
as possible (and preferable with data blocks of less than 512 bytes), and VS1011 makes every attempt
to keep its input buffer half full by changing its playback speed upto 5%. For best quality sound, the
average speed error should be within 0.5%, the bitrate should not exceed 160 kbit/s and VBR should not
be used. For details, see Application Notes for VS10XX.
SM SETTOZERO should always be set to 0.
SM DACT defines the active edge of data clock for SDI. If clear data is read at the rising edge, and if set
data is read at the falling edge.
When SM SDIORD is clear, bytes on SDI are sent as a default MSb first. By setting SM SDIORD, the
user may reverse the bit order for SDI, i.e. bit 0 is received first and bit 7 last. Bytes are, however, still
sent in the default order. This register bit has no effect on the SCI bus.
Setting SM SDISHARE makes SCI and SDI share the same chip select, as explained in Chapter 7.2, if
also SM SDINEW is set.
Setting SM SDINEW will activate VS1002 native serial modes as described in Chapters 7.2.1 and 7.3.2.
8.6.2 SCI STATUS (RW)
SCI STATUS contains information on the current status of VS1011 and lets the user shutdown the chip
without audio glitches.
Name
Bits Description
SS VER
6..4 Version
SS APDOWN2 3 Analog driver powerdown
SS APDOWN1 2 Analog internal powerdown
SS AVOL
1..0 Analog volume control
SS VER is 0 for VS1001, 1 for VS1011, 2 for VS1002 and 3 for vs1003.
SS APDOWN2 controls analog driver powerdown. Normally this bit is controlled by the system firmware.
However, if the user wants to powerdown VS1011 with a minimum power-off transient, turn this bit to 1,
then wait for at least a few milliseconds before activating reset. For more details, see Application Notes
for VS10XX.
SS APDOWN1 controls internal analog powerdown. This bit is meant to be used by the system firmware
only.
SS AVOL is the analog volume control: 0 = -0 dB, 1 = -6 dB, 3 = -12 dB. This register is meant to be
used automatically by the system firmware only.
Version 0.71, 2004-07-20
26