WM9713L_06 WOLFSON [Wolfson Microelectronics plc], WM9713L_06 Datasheet - Page 20

• Manufacturer Part Number: WM9713L_06
• Description: AC 97 Audio + Touchpanel CODEC
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM9713L
PCM INTERFACE
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Figure 4 AC-Link Interface (typical case with BITCLK generated by the AC97 codec)
The SDATAIN and SDATAOUT signals each carry 13 time-division multiplexed data streams (slots 0
to 12). A complete sequence of slots 0 to 12 is referred to as an AC-Link frame, and contains a total
of 256 bits. The frame rate is 48kHz. This makes it possible to simultaneously transmit and receive
multiple data streams (e.g. audio, touchpanel, AUXDAC, control) at sample rates up to 48kHz.
Detailed information can be found in the AC’97 (Revision 2.2) specification, which can be obtained at
www.intel.com/design/chipsets/audio/
Note:
SDATAOUT and SYNC must be held low when RESETB is applied. These signals must be held low
for the entire duration of the RESETB pulse and especially during the low-to-high transition of
RESETB. If SDATAOUT or SYNC is high during reset, the WM9713L may enter test modes.
Information relating to this operation is available in the AC'97 specification or in Wolfson applications
note WAN-0104 available at www.wolfsonmirco.com.
OPERATION
WM9713L can implement a PCM voice codec function using the dedicated VXDAC and either one or
both of the existing hi-fi ADC’s. In PCM codec mode, VXDAC input and ADC output are interfaced
via a PCM style port via GPIO pins.
This interface can support one ADC channel, or stereo/dual ADC channels if required, (two channels
of data are sent per PCM frame as back to back words).
In voice only mode, the AC link is used only for control information, not audio data. Therefore it will
generally be shut down (PR4=1), except when control data must be sent.
The PCM interface makes use of 4 of the GPIO interface pins, for clock, frame, and data in/out. If the
PCM codec function is not enabled then the GPIO pins may be used for other functions.
INTERFACE PROTOCOL
The WM9713L PCM audio interface is used for the input of data to the Voice DAC and the output of
data from the Stereo ADC. When enabled, the PCM audio interface uses four GPIO pins:
Depending on the mode of operation (see “PCM Interface Modes”), at least one of these four pins
must be set up as an output by writing to register 4Ch (see Table 62). When not enabled the GPIOs
may be used for other functions on the WM9713L.
GPIO1/PCMCLK: Bit clock
GPIO3/PCMFS: Frame Sync
GPIO4/PCMDAC: Voice DAC data input
GPIO5/PCMADC: Stereo ADC data output
PP Rev 3.0 June 2006
Pre-Production
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