YMF744B Datasheet, PDF (49/60 Pages) List of Unclassifed Manufacturers – DS-1S

YMF744B
7. Zoomed Video Port
Zoomed Video Port is defined in the PC Card Standard (PCMCIA) applicable to the notebook PC or other
systems. This port is used to directly output video and/or audio signals onto the PCMCIA bus for D/A
conversion process, and connect them directly to the video and/or audio signal processing chips on the PC
system. Its major applications include MPEG decoder card and video capture card, etc.
Because the video and/or audio signals on the Zoomed Video Port have been output in synchronized
condition, DS-1S only converts input audio signal into analog signal through D/A converter.
Audio signals to be transferred on the Zoomed Video Port include bit clock (SCLK), L/R clock (LRCK) and
serial data (DATA), and they are provided as outputs in the format defined below. This is generally called
I²S format.
SCLK
DATA
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
LRCK
LEFT Channel
RIGHT Channel
In the Zoomed Video Port, synchronization with a master clock supplied from the bus is inherently required.
However, DS-1S can asynchronously process audio signal input via the Zoomed Video Port, eliminating the
need for master clock.
Sampling rate of the audio signals input via the Zoomed Video Port is resampled to 96.0kHz sampling
frequency at the stage followed by the SRC block, then converted to 48.0kHz sampling rate in the SRC block
stage. Sampling rates to be supported on the Zoomed Video Port include 22.05kHz, 32.0kHz, 44.1kHz and
48.0kHz.
Interface connection arrangement between the DS-1S and the Zoomed Video Port is as illustrated below.
DS-1S
ZVBCLK ⁸⁰
ZVLRCK ⁷⁹
ZVSDI ⁷⁸
ZV Port
SCLK
LRCK
DATA
MCLK
Open
The Zoomed Video Port can be used to be selected between the SPDIFIN input.
February 3, 1999
-49-