WM9713L
Preliminary Technical Data
DEVICE DESCRIPTION
INTRODUCTION
The WM9713L is a largely pin compatible upgrade to WM9712, with a PCM voice codec added. This
codec is interfaced via a PCM type audio interface which makes use of GPIO pins for connection.
It is designed to meet the mixed-signal requirements of portable and wireless smartphone systems. It
includes audio recording and playback, touchpanel digitisation, battery monitoring, auxiliary ADC and
GPIO functions, all controlled through a single 5-wire AC-Link interface. Additionally, PCM voice
codec functions are supported through provision of an additional voice DAC and a PCM audio serial
interface.
A PLL is included to allow unrelated reference clocks to be used for generation of the AC link system
clock. Typically 13MHz or 2.048MHz references might be used as a reference.
SOFTWARE SUPPORT
The basic audio features of the WM9713L are software compatible with standard AC’97 device
drivers. However, to better support the touchpanel and other additional functions, Wolfson
Microelectronics supplies custom device drivers for selected CPUs and operating systems. Please
contact your local Wolfson Sales Office for more information.
AC’97 COMPATIBILITY
The WM9713L uses an AC’97 interface to communicate with a microprocessor or controller. The
audio and GPIO functions are largely compliant with AC’97 Revision 2.2. The following differences
from the AC’97 standard are noted:
•
Pinout: The function of some pins has been changed to support device specific
features. The PHONE and PCBEEP pins have been moved to different locations
on the device package.
•
•
Package: The default package for the WM9713L is a 7×7mm leadless QFN
package.
Audio mixing: The WM9713L handles all the audio functions of a smartphone,
including audio playback, voice recording, phone calls, phone call recording, ring
tones, as well as simultaneous use of these features. The AC’97 mixer architecture
does not fully support this. The WM9713L therefore uses a modified AC’97 mixer
architecture with three separate mixers.
•
Tone Control, Bass Boost and 3D Enhancement: These functions are implemented
in the digital domain and therefore affect only signals being played through the
audio DACs, not all output signals as stipulated in AC’97.
Some other functions are additional to AC’97:
•
•
•
•
•
•
•
•
•
On-chip BTL loudspeaker driver for mono or stereo speakers
On-chip BTL driver for ear speaker (phone receiver)
Auxiliary mono DAC for ring tones, system alerts etc.
Touchpanel controller
Auxiliary ADC Inputs
2 Analogue Comparators for Battery Alarm
Programmable Filter Characteristics for Tone Control and 3D Enhancement
PCM interface to additional Voice DAC and existing audio ADCs
PLL to create AC’97 system clock from unrelated reference clock input
PTD, March 2004, Rev 2.2
1
14
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
