Data Sheet

Everestek Inc.
www.everestek.biz Page 10
6. I2S Format
ETK51 I2S data in and data out share the same LRCK and BCK pins. ETK51 can work in master
mode and slave mode. The audio sampling rate can be 32/44.1/48K.
In master mode, ETK51 will generate I2S_MCLK/LRCK/BCK for external audio codec. In slave
mode, ETK51 will receive external LRCK/BCK signal.
ETK51 has a digital controlled PLL, so the clock jitter noise will not be a problem in Rx.
During operate in slave mode, ETK51 will tracking external audio clock to make Tx and Rx work in
the same frequency.
Mono channel data can feed through left channel (Lch) or right channel (Rch).
If 2(stereo) or 1(mono) channel application, Tx I2S signal connection as followed,
LRCK
BCK
DIN(stereo)
P1.2
P1.3
P1.1
Tx
MCLKMCLK(256Fs)
Noe: if modle i operaed in I2S lae mode, modle don need MCLK ignal. Only need BCK,
LRCK, DIN signals.
ETK51 work in 64 Fs mode. This means total 64 BCK pulse in one LRCK cycle. The I2S signal as
the chart followed,
0 1 2 3
15
16 17 18 19 23 25 26 3124 0 1 2 3
15
16 17 18 19 23 25 2624
23 22 21 89 7 6 5 1 0
LRCK
BCK
23 22 21 89 7 6 5 1 0
DATA
I2S master mode (Tx and Rx site) switching characteristics
Symbol
Min
Typ
Max
Unit
MCLK
256fs
Hz
BCK
64fs
Hz
Duty (MCLK, BCK)
50
%
Symbol
Min
Typ
Max
Unit
Note
tBKLR
-1
+1
ns
tBKDO (Rx only)
-1
+1
ns
BCK falling edge to DOUT transient