SM5846AP_06 Datasheet, PDF (25/36 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:
I 20/24-bit data length
I Simultaneous left/right-channel serial data trans-
mission
I MSB first
I Bit transfer clock burst (NPC format)
I 2s complement for negative values
Audio data output interface pins
Audio data is output using pins WCKO, BCKO,
DOL and DIN.
Pin name
WCKO
BCKO
DOL
DOR
Function
Word clock output
Bit transfer clock output
Left-channel serial data output
Right-channel serial data output
Serial data is output on DOL and DOR on the falling
edge of the bit transfer clock BCKO. Generally,
external circuits, such as a serial D/A converter, sam-
ple 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.
Output data length select
The output data length is set by either the OBS pin or
flag.
OBS
HIGH
LOW
Output data
length
24 bits
20 bits
Notes
The OBS flag is set LOW
(default) after a system reset.
SEIKO NPC CORPORATION —25