Cirrus Logic CS42L42 Manual page 57

4.8.7 Payload Transport
This section introduces describes how payload data is organized within a SoundWire frame and the control registers that
define where each port's payload data is located in the frame.
OFFSET
HSTART HSTOP
C
o
Ch0 N
n
Ch1 N
t
r
o
l
C
o
Ch0 N+1
n
Ch1 N+1
t
r
o
l
Two-Channel PCM Data, One Sample per Frame
SoundWire Frame Rate = 48 kHz
Sample Interval Rate = 48 kHz
Figure 4-25. Examples of Register Settings Defining a Port's Payload Data Location
Basic parameters in Fig. 4-25
• SINTERVAL—Defines the sample interval in units of bit slots.
• HSTART and HSTOP—Define the column boundaries of the transport window.
• OFFSET—Defines the offset in units of bit slots from the start of the transport window where the data is located.
• WORD_LENGTH—Number of bits in each channel minus 1.
Additional parameters are described in the SoundWire register descriptions in
• Payload channel sample—Refers to one sample per channel per sample interval.
• Payload data block refers to blocks of data within a frame, as controlled by
and shown in Fig. 4-26:
— Blocks-per-Channel Mode—Each payload data block contains one channel sample. There may be multiple
payload data blocks per frame, each containing a sample from a different channel.
— Blocks-per-Port Mode—One block for the port in the frame contains all the port's channel samples concatenated.
DS1083F2
WLENGTH * #CH BitSlots
include the following:
Fig. 4-25 shows examples of how the data is positioned.
HSTART HSTOP
C
o
n
t
r
o
l
C
o
n
t
r
o
Ch0 6x4
l
Ch1 6x4
C
o
n
t
r
o
l
C
o
n
t
r
o
Ch0 6x4
l
Ch1 6x4
Multiframe Mode, Two-Channel PCM Data, Every Other Frame
SoundWire Frame Rate = 48 kHz
Sample Interval Rate = 24 kHz
Section 7.1
BLOCK_PACKING_MODE
CS42L42
4.8 SoundWire Interface
OFFSET
and Section 7.2.
(see p. 127)
57