CS43130 Datasheet, PDF (85/137 Pages) Cirrus Logic – 130-dB, 32-Bit High-Performance DAC with Integrated Headphone Driver

CS43130
5.11 Headphone Load Measurement
5.11.2 Measuring DC Impedance
Fig. 5-3 shows and Ex. 5-21 describes the steps necessary for measuring DC impedance with the following assumptions:
• The CS43130 is already powered up and out of reset.
• MCLK_INT is 22.5792 or 24.576 MHz sourced from MCLK/XTAL or PLL (MCLK_SRC_SEL = 00 or 01).
• HP_IN_EN = 0 and HPLOAD_EN = 0.
• A headphone is already plugged in and HPDETECT_PLUG_INT = 1.
Enable Impedance Measurement
Subsystem has already been run.
DC Impedance Measurement
A
Select Channel A
0x10010 = 0x99
0x10026 = 0x0 A
0x10027 = 0x93
0x10028 = 0x0 A
0x10010 = 0x00
HPLOAD_CHN_SEL = 0 (Channel A)
HPLOAD_DC_START = 0 (Stop)
Channel ?
B
Select Channel B
0x10010 = 0x99
0x10026 = 0x8 A
0x10027 = 0x15
0x10028 = 0x06
0x10010 = 0x00
HPLOAD_CHN_SEL = 1 (Channel B)
HPLOAD_DC_START = 0 (Stop)
Enable DC impedance measurement
HPLOAD_DC_START = 1
Assumptions
DAC Response
User Commands
HPLOAD _DC_DONE_ INT
= 1?
NO
YES
NO
HPLOAD_UNPLUG_INT
= 1?
YES
HPLOAD_UNPLUG_INT NO
= 1?
Read DC impedance
HPLOAD _OOR_INT
= 1?
NO
value from
RL_DC_STAT_0 and
RL_ DC_STAT_1
YES
Error Occurred
YES
New
Measurement?
NO
YES
Disable Impedance Measurement
Subsystem
AC Impedance Measurement
Or
Disable Impedance Measurement Subsystem
Figure 5-3. DC Impedance Measurement Flowchart
Example 5-21. Sequence for DC Impedance Measurement
STEP
TASK
REGISTER/BIT FIELDS
1 Enable impedance measurement subsystem. Refer to Ex. 5-20.
VALUE
DESCRIPTION
DS1073F1
85