CS43L21 datasheet(26/63 Pages) CIRRUS

26 / 63 page

DS723A1

CS43L21

4.3.5

Tone Control

Shelving filters are used to implement bass and treble (boost and cut) with four selectable corner frequen-

cies. Boosting will affect peak detect and limiting when levels exceed the maximum threshold settings.

4.3.6

Limiter

When enabled, the limiter monitors the digital input signal before the DAC modulator, detects when levels

exceed the maximum threshold settings and lowers the AOUT volume at a programmable attack rate be-

low the maximum threshold. When the input signal level falls below the maximum threshold, the AOUT

volume returns to its original level set in the Volume Control register at a programmable release rate. At-

tack and release rates are affected by the DAC soft ramp/zero cross settings and sample rate, Fs. Limiter

soft ramp and zero cross dependency may be independently enabled/disabled.

Recommended settings: Best limiting performance may be realized with the fastest attack and slowest

release setting with soft ramp enabled in the control registers. The “cushion” bits allow the user to set a

threshold slightly below the maximum threshold for hysteresis control - this cushions the sound as the lim-

iter attacks and releases.

Note:

When the Limiter is enabled, the AOUT Volume is automatically controlled and should not be adjusted

manually. Alternative volume control may be realized using the PCMMIXx_VOL[6:0] bits.

The Limiter maintains the output signal between the CUSH and MAX thresholds. As the digital input

signal level changes, the level-controlled output may not always be the same but will always fall within

the thresholds.

Software

Controls:

“Tone Control (Address 15h)” on page 48.

Software

Controls:

“Limiter Release Rate Register (Address 1Ah)” on page 51, “Limiter Attack Rate Register (Address

1Bh)” on page 52, “DAC Control (Address 09h)” on page 42

FREQ[3:0]

...

BPVOL[4:0]

ONTIME[3:0]

OFFTIME[2:0]

REPEAT = '0'

BEEP = '1'

REPEAT = '1'

BEEP = '0'

REPEAT = '1'

BEEP = '1'

SINGLE-BEEP: Beep turns on at a

configurable frequency (FREQ) and

volume (BPVOL) for the duration of

ONTIME. BEEP must be cleared

and set for additional beeps.

MULTI-BEEP: Beep turns on at a configurable frequency (FREQ)

and volume (BPVOL) for the duration of ONTIME and turns off for

the duration of OFFTIME. On and off cycles are repeated until

REPEAT is cleared.

CONTINUOUS BEEP: Beep turns on at a configurable frequency (FREQ) and volume (BPVOL) and remains

on until REPEAT is cleared.

Figure 10. Beep Configuration Options

CS43L21 bảng dữ liệu(PDF) 26 Page - Cirrus Logic

CS43L21 bảng dữ liệu(HTML) 26 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

bảng dữ liệu tải về

Link URL