CS43131 datasheet(104/156 Pages) CIRRUS

104 / 156 page

104

DS1155F1

CS43131

5.14 Headphone Load Measurement

Ex. 5-20 demonstrates measuring both AC and DC impedance for both channels of the CS43131.

Example 5-20. AC and DC Impedance Measurement

STEP

TASK

VALUE

DESCRIPTION

Read Interrupt Status 4 register (0xF0003) to clear sticky bits.

Enable HP Load Interrupts

Interrupt Mask 4. 0xF0013

0x00

HPLOAD_NO_DC_INT_MASK

HPLOAD_UNPLUG_INT_MASK

HPLOAD_HPON_INT_MASK

HPLOAD_OOR_INT_MASK

HPLOAD_AC_DONE_INT_MASK

HPLOAD_DC_DONE_INT_MASK

HPLOAD_OFF_INT_MASK

HPLOAD_ON_INT_MASK

Enable HPLOAD_NO_DC interrupt

Enable HPLOAD_UNPLUG interrupt

Enable HPLOAD_HPON interrupt

Enable HPLOAD_OOR interrupt

Enable HPLOAD_AC_DONE interrupt

Enable HPLOAD_DC_DONE interrupt

Enable HPLOAD_OFF interrupt

Enable HPLOAD_ON interrupt

Select Channel A

HP Load 1. 0xE0000

0x00

HPLOAD_EN

Reserved

HPLOAD_CHN_SEL

Reserved

HPLOAD_AC_START

HPLOAD_DC_START

HPOUTA selected

Enable impedance subsystem

HP Load 1. 0xE0000

0x80

HPLOAD_EN

Reserved

HPLOAD_CHN_SEL

Reserved

HPLOAD_AC_START

HPLOAD_DC_START

Enable impedance subsystem

Wait for interrupt. Check if HPLOAD_ON_INT = 1 in Interrupt Status 4 register (0xF0003)

Start DC impedance measurement

HP Load 1. 0xE0000

0x81

HPLOAD_EN

Reserved

HPLOAD_CHN_SEL

Reserved

HPLOAD_AC_START

HPLOAD_DC_START

Start DC impedance measurement

Wait for interrupt. Read Interrupt Status 4 register (0xF0003). If HPLOAD_UNPLUG_INT = 1, go to the last step as an error has occurred. If

HPLOAD_OOR_INT = 1, go to the last step as an error has occurred. Otherwise, if HPLOAD_DC_DONE_INT = 1, go to the next step.

DC impedance values are available in HP DC Load Status 0 (0xE000D) and HP DC Load Status 1 (0xE000E) registers.

Set HP load measurement frequency to

desired frequency. Assuming 1 kHz.

HP Load Measurement 1. 0xE0003

0xA8

HPLOAD_MEAS_FREQ_LSB

0xA8

Set measurement frequency = 1 kHz

HP Load Measurement 2. 0xE0004

0x00

HPLOAD_MEAS_FREQ_MSB

0x00

MSB of load measurement frequency

Start AC impedance measurement

HP Load 1. 0xE0000

0x82

HPLOAD_EN

Reserved

HPLOAD_CHN_SEL

Reserved

HPLOAD_AC_START

HPLOAD_DC_START

Start AC impedance measurement

Wait for interrupt. Read Interrupt Status 4 register (0xF0003). If HPLOAD_UNPLUG_INT = 1, go to the last step as an error has occurred. If

HPLOAD_OOR_INT = 1, go to the last step as an error has occurred. Otherwise, if HPLOAD_AC_DONE_INT = 1, go to the next step.

AC impedance values are available in HP AC Load Status 0 (0xE0010) and HP AC Load Status 1 (0xE0011) registers.

Stop AC impedance measurement.

HP Load 1. 0xE0000

0x80

If another frequency point is desired, go back to step 9. Otherwise continue.

Disable impedance measurement

subsystem and select channel B

HP Load 1. 0xE0000

0x10

Wait for interrupt. Read Interrupt Status 4 register (0xF0003). Check for HPLOAD_OFF_INT = 1. If Channel B measurement is desired, continue

to the next step; otherwise go to step 30 to end the impedance measurement.

Enable impedance subsystem

HP Load 1. 0xE0000

0x90

HPLOAD_EN

Reserved

HPLOAD_CHN_SEL

Reserved

HPLOAD_AC_START

HPLOAD_DC_START

Enable impedance subsystem

HPOUTB selected

Wait for interrupt. Check if HPLOAD_ON_INT = 1 in Interrupt Status 4 register (0xF0003)

CS43131 датащи(PDF) 104 Page - Cirrus Logic

CS43131 датащи(HTML) 104 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL