WM8706

Production Data

w

PD Rev 4.1 July 2005

11

In left justified, right justified and I

is 2 times the selected word length. LRCIN must be high for a minimum of word length BCKINs

and low for a minimum of word length BCKINs. Any mark to space ratio on LRCIN is

acceptable provided the above requirements are met. The WM8706 will automatically detect

when data with a LRCIN period of exactly 32 is sent, and select 16 bit mode - overriding any

previously programmed word length. Word length will revert to the previously programmed

value when a LRCIN period other than 32 is detected. (see Figure 4, Figure 5 and Figure 6).

In DSP early or DSP late mode, the data is time multiplexed onto DIN. LRCIN is used as a

frame sync signal to identify the MSB of the first word. The minimum number of BCKINs per

LRCIN period is 2 times the selected word length. Any mark to space ratio is acceptable on

LRCIN provided the rising edge is correctly positioned (see Figure 7 and Figure 8).

LEFT JUSTIFIED MODE

In left justified mode, the MSB is sampled on the first rising edge of BCKIN following a LRCIN

transition. LRCIN is high during the left samples and low during the right samples.

LEFT CHANNEL

RIGHT CHANNEL

LRCIN

BCKIN

DIN

1/fs

n

3

2

1

n-2 n-1

LSB

MSB

n

3

2

1

n-2 n-1

LSB

MSB

Figure 4 Left Justified Mode Timing Diagram

RIGHT JUSTIFIED MODE

In right justified mode, the LSB is sampled on the rising edge of BCKIN preceding a LRCIN

transition. LRCIN is high during the left samples and low during the right samples.

LEFT CHANNEL

RIGHT CHANNEL

LRCIN

BCKIN

DIN

1/fs

n

3

2

1

n-2 n-1

LSB

MSB

n

3

2

1

n-2 n-1

LSB

MSB

Figure 5 Right Justified Mode Timing Diagram