WM8716 Production Data
w PD Rev 4.1 September 2006
10
AUDIO DATA INTERFACE
Data may be input at a rate corresponding to the system clock having a rate of 256fs or 384fs or
512fs or 768fs , in which c ase an ov ersampli ng ratio of 128x is select ed. Alt ernatively a rate of 128fs
or 192fs may be used, in which case the first filter stage is bypassed and an oversampling ratio of
64x results. Finally, in MODE8X, data may be input at 8x the normal rate, in which case separate
input pins are used to input the two stereo channels of data (unless DIFFHW mode and MODE8X
are both s el ec ted, i n whic h case only a m ono c hannel i s converted differential ly). In MODE8X all filter
stages are by-passed, prior to the sigma delta modulator. Data is input MSB first in all modes.
NORM AL SAMPLE RATE
In normal mode, the data is input serially on one pin for both left and right channels.
Data can be “right jus tified” m eaning that the last 16, 20 or 24 bits (depending on chosen PCM word
length) that were clocked in pri or to the transition on LRCIN are valid.
Alternat ively data can be “left justifi ed” (20 and 24-bit PCM data onl y), where the bits ar e clocked in
as the first 20 or 24 bits after a transi tion on LRCIN.
For the three I
2
S m odes s upported (16-bit , 20-bit and 24-bit PCM data), data is cloc ked “left jus ti fied”
except with one additional preceding clock cycle.
LRCIN (PIN 1)
16-BIT RIGHT
JUSTIFIED
DIN (PIN 2)
20-BIT RIGHT
JUSTIFIED
DIN (PIN 2)
24-BIT RIGHT
JUSTIFIED
DIN (PIN 2)
24-BIT LEFT
JUSTIFIED
DIN (PIN 2)
20-BIT LEFT
JUSTIFIED
DIN (PIN 2)
BCKIN (PIN 3)
B2 B1 B0
B2 B1 B0
B2 B1 B0
B0
B0
B23 B22 B21
B19 B18 B17
B23 B22 B21 B20 B19
B4 B3 B2 B1 B0
B0
B19 B18 B17
B15 B2 B1 B0
B2 B1 B0
B2 B1 B0
B23 B22 B21
B19 B18 B17 B0
B4 B3 B2 B1 B0
B23 B22 B21 B20 B19
B19 B18 B17
B15 B2 B1 B0
B2 B1 B0
B2 B1 B0
RIGHTLEFT
1/fs
LRCIN (PIN 1)
16-BIT I
2
S
DIN (PIN 2)
24-BIT I
2
S
DIN (PIN 2)
20-BIT I
2
S
DIN (PIN 2)
BCKIN (PIN 3)
B2 B1 B0
B0
B2 B1 B0
B3 B2 B1
RIGHTLEFT
B15
B23
B19
B6 B5 B4
B2 B1 B0
B3 B2 B1
B15
B23
B19
B6 B5 B4 B0
B2 B1 B0
B23
B19
B15
Figure 4 Audio Data Input Format
