Datasheet

SRC4192, SRC4193
SBFS022B
18
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MODE2 MODE1 MODE0 SERIAL PORT MODE
0 0 0 Both Input and Output Ports are Slave mode
0 0 1 Output Port is Master mode with RCKI = 128f
S
0 1 0 Output Port is Master mode with RCKI = 512f
S
0 1 1 Output Port is Master mode with RCKI = 256f
S
1 0 0 Both Input and Output Ports are Slave Mode
1 0 1 Input Port is Master mode with RCKI = 128f
S
1 1 0 Input Port is Master mode with RCKI = 512f
S
1 1 1 Input Port is Master mode with RCKI = 256f
S
AUDIO PORT MODES
The SRC4192 and SRC4193 both support seven serial port
modes, which are shown in Table 1. For the SRC4192, the
audio port mode is selected using the MODE0 (pin 26),
MODE1 (pin 27), and MODE2 (pin 28) inputs. For the
SRC4193, the mode is selected using the MODE[2:0] bits in
Control Register 1. The default mode setting for the SRC4193
is both input and output ports set to Slave mode.
In Slave mode, the port LRCK and BCK clocks are config-
ured as inputs, and receive their clocks from an external
audio device. In Master mode, the LRCK and BCK clocks are
configured as outputs, being derived from the reference
clock input (RCKI). Only one port can be set to Master mode
at any given time, as indicated in Table 1.
INPUT PORT OPERATION
The audio input port is a three-wire synchronous serial
interface that may operate in either Slave or Master mode.
The SDIN input (pin 4) is the serial audio data input. Audio
data is input at this pin in one of three standard audio data
formats: Philips I
2
S, Left Justified, or Right Justified. The
audio data word length may be up to 24-bits for I
2
S and Left
Justified formats, while the Right Justified format supports
16-, 18-, 20-, or 24-bit data. The data formats are shown in
Figure 4, while critical timing parameters are shown in Figure
5 and listed in the Electrical Characteristics table.
t
LRIS
t
SIH
t
LDIS
t
SIL
t
LDIH
LRCKI
BCKI
SDIN
TABLE 1. Setting the Serial Port Modes.
Left Channel
(a) Left Justified Data Format
(b) Right Justified Data Format
Right Channel
LRCKO
BCKI
SDIN
MSB LSB LSBMSB
LRCKI
BCKI
SDIN
MSB MSB LSBLSB
(c) I
2
S Data Format
1/f
S
LRCKI
BCKI
SDIN
MSB LSB MSB LSB
FIGURE 4. Input Data Formats.
FIGURE 5. Input Port Timing.