WM8721

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WOLFSON MICROELECTRONICS LTD

PP Rev 1.3 November 2000

14

The software control is given in Table 4.

REGISTER

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

6:0

LHPVOL[6:0]

1111001

( 0dB )

Left Channel Headphone Output

Volume Control

1111111 = +6dB

. . 1dB steps down to

0110000 = -73dB

0000000 to 0101111 = MUTE

7

LZCEN

1

Left Channel Zero Cross detect

Enable

1 = Enable

0 = Disable

0000010

Left

Headphone

Out

8

LRHPBOTH

0

Left to Right Channel Headphone

Volume, Mute and Zero Cross Data

Load Control

1 = Enable Simultaneous Load of

LHPVOL[7:0] and LZCEN to

RHPVOL[7:0] and RZCEN

0 = Disable Simultaneous Load

6:0

RHPVOL[7:0]

1111001

( 0dB )

Right Channel Headphone Output

Volume Control

1111111 = +6dB

. . 1dB steps down to

0110000 = -73dB

0000000 to 0101111 = MUTE

7

RZCEN

1

Right Channel Zero Cross Detect

Enable

1 = Enable

0 = Disable

0000011

Right

Headphone

Out

8

RLHPBOTH

0

Right to Left Channel Headphone

Volume, Mute and Zero Cross Data

Load Control

1 = Enable Simultaneous Load of

RHPVOL[7:0] and RZCEN to

LHPVOL[7:0] and LZCEN

0 = Disable Simultaneous Load

Table 4 Headphone Output Software Control

The recommended external components required to complete the application are shown in Figure 11.

AGND

R1

C1

AGND

HPOUT

Figure 11 Headphone Output Application Drawing