Cirrus Logic CS42L42 Manual page 118

Bits Name
1 CLOCK_ Clock stop now (write only). Informs the slave whether the master is shutting down the SoundWire clock at the end of the
STOP_ next frame.
NOW
0 (Default) Normal operation
1 Clock stops after one more frame. The master is shutting down the SoundWire clock at the end of the next SoundWire
frame. The master sends one more frame, which contains a Ping command where the master owns all payload data
bit slots. The clock is stopped after the falling edge of the clock for that frame. The asynchronous wake event is
allowed to propagate to the data pin only while the clock is stopped. To enter clock stop, the SoundWire master must
first set CLOCK_STOP_PREPARE and wait for CLOCK_STOP_NOT_FINISHED to be cleared before setting this bit.
0 CLOCK_ Clock stop not finished. Indicates whether the chip completed any necessary shutdown sequence and is ready for the
STOP_ SoundWire master to set CLOCK_STOP_NOW and shut down the SoundWire clock. The encoding allows a SoundWire
NOT_ group read to identify when all SoundWire slaves are ready to enter Clock Stop State.
FINISHED
0 Ready for clock stop.
1 (Default) Not finished with state transition requested by the current value of CLOCK_STOP_PREPARE.
7.1.4 SCP System Control
7 6
Default 0 0
Bits Name
7:4 — Reserved
3 WAKE_ Clock Stop Mode wake-up enable. Used to enable asynchronous wake from Clock Stop Mode when an S0 button press,
UP_ headphone plug, or headphone unplug occurs.
ENABLE
0 (Default) Asynchronous wake disabled.
1 Asynchronous wake enabled.
2 CLOCK_ Clock Stop Mode. Allow the SoundWire slave to lose context coming out of Clock Stop Mode.
STOP_
0 (Default) Slave must not lose context in Clock Stop Mode
MODE
1 Slave loses context and triggers a SoundWire hard reset on exit from Clock Stop Mode
1 — Reserved
0 CLOCK_ Clock stop prepare. Indicates whether the SoundWire master intends to stop the SoundWire clock. See
STOP_
0 (Default) Clock stop not requested.
PREPARE
1 The CS42L42 is notified to prepare for clock stop.
7.1.5 SCP Device Number
7
—
—
Default 0
Note: This register can be written only if SoundWire slave has enumeration on. See note in
Bits Name
7:6 — Reserved
5:4 GROUP_ Group ID. Indicates whether this SoundWire slave device is addressed by a shared group alias in addition to commands
ID targeted to its own device number.
00 (Default) Normal, not in a shared group.
01 Group 12: The device reacts to any command directed to the DevAddr = 12 alias.
10 Group 13: The device reacts to any command directed to the DevAddr = 13 alias.
11 Reserved
3:0 DEVICE_ Device number. This value is compared with the DevAddr field in the control word to determine whether the command is
NUMBER directed to this device. Attempts to write to this bit are ignored if the SoundWire slave is not in the Enumeration ON State.
See note in
0000–1011 Valid device numbers (0–11 decimal).
1100–1111 Reserved
DS1083F2
5 4
— WAKE_UP_ENABLE CLOCK_STOP_MODE
—
0 0
6 5
GROUP_ID
0 0
Section 7.1.8.
7.1 SoundWire Control Port 0 Registers
Description
3 2
R/W R/W
0 0
Description
4 3
R/W
0 0
Section
Description
CS42L42
Address Base + 0x45
1 0
— CLOCK_STOP_PREPARE
— R/W
0 0
Section
Address Base + 0x46
2 1
DEVICE_NUMBER
0 0
7.1.8.
4.8.13.
0
0
118