WM8987 datasheet(37/59 Pages) WOLFSON

37 / 59 page

Production Data

WM8987L

PD Rev 4.0 August 2008

AUDIO DATA FORMATS

In Left Justified mode, the MSB is available on the first rising edge of BCLK following a LRCLK

transition. The other bits up to the LSB are then transmitted in order. Depending on word length,

BCLK frequency and sample rate, there may be unused BCLK cycles before each LRCLK transition.

Figure 13 Left Justified Audio Interface (assuming n-bit word length)

In I2S mode, the MSB is available on the second rising edge of BCLK following a LRCLK transition.

The other bits up to the LSB are then transmitted in order. Depending on word length, BCLK

frequency and sample rate, there may be unused BCLK cycles between the LSB of one sample and

the MSB of the next.

Figure 14 I2S Justified Audio Interface (assuming n-bit word length)

In DSP/PCM mode, the left channel MSB is available on either the 1st (mode B) or 2nd (mode A)

rising edge of BCLK (selectable by LRP) following a rising edge of LRC. Right channel data

immediately follows left channel data. Depending on word length, BCLK frequency and sample rate,

there may be unused BCLK cycles between the LSB of the right channel data and the next sample.

In device master mode, the LRC output will resemble the frame pulse shown in Figure 15 and Figure

16. In device slave mode, Figure 17 and Figure 18, it is possible to use any length of frame pulse

less than 1/fs, providing the falling edge of the frame pulse occurs greater than one BCLK period

before the rising edge of the next frame pulse.

WM8987 Datasheet(PDF) 37 Page - Wolfson Microelectronics plc