wm9714l Wolfson Microelectronics plc, wm9714l Datasheet - Page 59

• Manufacturer Part Number: wm9714l
• Description: Ac?97 Audio Codec
• Manufacturer: Wolfson Microelectronics plc

Pre-Production
JACK INSERTION AND AUTO-SWITCHING
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In a phone application, a BTL ear speaker may be connected across MONO and HPL, a stereo
headphone on HPL and HPR and stereo speakers on SPKL, SPKR, OUT3 and OUT4 (see Figure
23). Typically, only one of these three output devices is used at any given time: when no headphone
is plugged in, the BTL ear speaker or stereo speakers are active, otherwise the headphone is used.
Figure 23 Typical Output Configuration
The presence of a headphone can be detected using one of GPIO1/6/7/8 (pins 44, 3, 11 & 12) and
an external pull-up resistor (see Figure 35, page 113 for a circuit diagram). When the jack is inserted,
the GPIO is pulled low by a switch on the socket. When the jack is removed the GPIO is pulled high
by a resistor. If the JIEN bit is set, the WM9714L automatically switches between headphone and
any other output configuration, typically ear speaker or stereo speaker that has been set up in the
Powerdown and Output PGA Mux Select registers.
Note:
Please refer to WAN_0182 for further information on jack detect configuration
In addition to the typical configuration explained above, the WM9714L can also support automatic
switching between the following three configurations set as BTL ear speaker and headphone.
Table 41 Ear Speaker Configuration
For example if OUT4 and HPL is selected as the BTL ear speaker, the user should select
EARSPKSEL = 3h, then OUT4 is tri-stated on jack insert to prevent sound across the ear speaker
during headphone operation and HPL volume is set to OUT4 volume on jack out to ensure correct
ear speaker operation. It should be noted that all other outputs except HPL, HPR and selected ear
24h
Output Volume
Mapping (Jack
Insert)
REGISTER
ADDRESS
1:0
BIT
EARSPKSEL
LABEL
DEFAULT
00
Ear Speaker Source Control
00 = Default, no ear speaker
01 = MONO and HPL driver selected
10 = OUT3 and HPL driver selected
11 = OUT4 and HPL driver selected
configuration selected.
as BTL ear speaker.
as BTL ear speaker.
as BTL ear speaker.
DESCRIPTION
PP, Rev 3.2, October 2008
WM9714L
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