Power Driver Integrated Full Digital Audio Amplifier
NTP-8230
7. AUDIO INPUT
7.1. I2S and Serial Audio Interface
NTP-8230 receives audio data through digital audio interface. There are 2 different formats generally
used in digital audio interface - the Inter-IC Sound (I2S) Interface and General Serial Audio Interface
(GSA). These two interfaces have some common features.
These interfaces use 2 clock lines and 1 data line to transfer audio data. One of these clock lines is the
WCK. A period of the WCK is same with sampling period of audio data. This property enables the clock
receiving device to synchronize data word-wise transmitting or receiving timing with clock generating
device. Another functional aspect of the WCK is indication of current channel. In I2S mode, low state of
the WCK indicates 1st channel or left channel, and high state of the WCK means 2nd channel or right
channel.
The other clock line is BCK. This clock line is used to synchronize bit-wise timing. The number of clock
for one WCK period can be selected on BCKS(Bit Clock Size Select) of register address 0x01.
NTP-8230 functions as a slave on the bus. In slave mode, NTP-8230 receives WCK and BCK from
external source. The data transfer is done via SDATA line. The data being synchronized with the BCK
must be loaded on this line. NTP-8230 reads data on the rising edge of the BCK. NTP-8230 reads data
from defined bit range of WCK period. The bit range is selected by the interface type.
The bit range for I2S is predefined. GSA interface can select a bit range with LRJ, MLF and BS of
register address 0x01. Please refer to in Figure 11
Copyright ⓒ NeoFidelity, Inc.
Page 15
Document Number: DS8230 draft ver. 0.1
2011-01-11
ETC [ ETC ]
