wm8918 Wolfson Microelectronics plc, wm8918 Datasheet - Page 82

• Manufacturer Part Number: wm8918
• Description: Ultra Low Power Dac For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

WM8918
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All four of these modes are MSB first. They are described in “Audio Data Formats (Normal Mode)”,
below. Refer to the “Signal Timing Requirements” section for timing information.
Time Division Multiplexing (TDM) is available in all four data format modes. The WM8918 can be
programmed to send and receive data in one of two time slots.
PCM operation is supported using the DSP mode.
MASTER AND SLAVE MODE OPERATION
The WM8918 digital audio interface can operate in master or slave mode, as shown in Figure 40 and
Figure 41.
Figure 40 Master Mode
In master mode, BCLK is derived from SYSCLK via a programmable division set by BCLK_DIV.
In master mode, LRCLK is derived from BCLK via a programmable division set by LRCLK_RATE.
The BCLK input to this divider may be internal or external, allowing mixed master and slave modes.
The direction of these signals and the clock frequencies are controlled as described in the “Digital
Audio Interface Control” section.
BCLK and LRCLK can be enabled as outputs in Slave mode, allowing mixed Master/Slave operation
- see “Digital Audio Interface Control”.
OPERATION WITH TDM
Time division multiplexing (TDM) allows multiple devices to transfer data simultaneously on the same
bus. The WM8918 supports TDM in master and slave modes for all data formats and word lengths.
TDM is enabled and configured using register bits defined in the “Digital Audio Interface Control”
section.
Figure 41 Slave Mode
PD, Rev 4.0, September 2010
Production Data
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