SM5846AP Datasheet, PDF (26/36 Pages) Nippon Precision Circuits Inc – Multi-function Digital Filter

SM5846AP
Audio Data Output Interface
Serial data transmission is used for the digital audio
data output.
The data has the following format:
s 20/24-bit data length
s Simultaneous left/right-channel serial data transmis-
sion
s MSB first
s Bit transfer clock burst (NPC format)
s 2s complement for negative values
Serial data is output on DOL and DOR on the fall-
ing edge of the bit transfer clock BCKO. Generally,
external circuits, such as a serial D/A converter,
sample the serial data output on DOL and DOR on
the rising edge of the bit transfer clock signal, and
then shift the data into a register. At the completion
of one data cycle (20/24-bit selectable) transfer, the
word clock WCKO goes LOW with a 50% duty
ratio. Then the external circuit writes parallel data to
a buffer register on the falling edge of word clock
WCKO.
Audio data output interface pins
Output data length select
Audio data is output using pins WCKO, BCKO, DOL _{The output data length is set by either the OBS pin}
and DIN.
or flag.
Pin name
WCKO
BCKO
DOL
DOR
Function
Word clock output
Bit transfer clock output
Left-channel serial data output
Right-channel serial data output
OBS
HIGH
LOW
Output data
length
24 bits
20 bits
Notes
The OBS flag is set LOW
(default) after a system reset.
Audio
ICs
NIPPON PRECISION CIRCUITS—26