WM8739LEDS datasheet(19/35 Pages) WOLFSON

19 / 35 page

WM8739 / WM8739L

Advanced Information

AI Rev 2.2 September 2001

BCLK

ADCDAT

ADCLRC

WM8739

ADC

DSP

ENCODER

Figure 17 Master Mode

As a slave device the WM8739 sequences the data transfer (ADCDAT) over the digital audio

interface in response to the external applied clocks (BCLK, ADCLRC). This is illustrated Figure 18.

BCLK

ADCDAT

ADCLRC

WM8739

ADC

DSP

ENCODER

Figure 18 Slave Mode

AUDIO DATA SAMPLING RATES

The WM8739 provides for two modes of operation (normal and USB) to generate the required ADC

sampling rate. Normal and USB modes are programmed under software control according to the

table below.

In Normal mode, the user controls the sample rate by using an appropriate MCLK or crystal

frequency and the sample rate control register setting. The WM8739 can support sample rates from

8ks/s up to 96ks/s.

In USB mode, the user must use a fixed MLCK or crystal frequency of 12MHz to generate sample

rates from 8ks/s to 96ks/s. It is called USB mode since the common USB (Universal Serial Bus)

clock is at 12MHz and the WM8739 can be directly used within such systems. WM8739 can

generate all the normal audio sample rates from this one Master Clock frequency, removing the need

for different master clocks or PLL circuits.

WM8739LEDS Datenblatt(PDF) 19 Page - Wolfson Microelectronics plc