Product Specs

Table Of Contents
44 I
2
S Inter-IC sound interface
Page
446
44 I
2
S Inter-IC sound interface
The I
2
S (Inter-IC Sound) module, supports the original two-channel I
2
S format, and left or right-aligned
formats. It implements EasyDMA for sample transfer directly to and from RAM without CPU intervention.
The I
2
S peripheral has the following main features:
Master and Slave mode
Simultaneous bi-directional (TX and RX) audio streaming
Original I
2
S and left- or right-aligned format
8, 16 and 24-bit sample width
Low-jitter Master Clock generator
Various sample rates
PSEL.MCK
PSEL.LRCK
PSEL.SCK
PSEL.SDIN PSEL.SDOUT
Figure 129: I
2
S master
44.1 Mode
The I
2
S protocol specification defines two modes of operation, Master and Slave.
The I
2
S mode decides which of the two sides (Master or Slave) shall provide the clock signals LRCK and
SCK, and these signals are always supplied by the Master to the Slave.
44.2 Transmitting and receiving
The I
2
S module supports both transmission (TX) and reception (RX) of serial data. In both cases the serial
data is shifted synchronously to the clock signals SCK and LRCK.
I2S
MCK
Div
Div
EasyDMA
TXD.PTR
RXD.PTR
RXTXD.MAXCNT
CONFIG.MODE
CONFIG.MCKFREQ
Master clock
generator
CONFIG.MCKEN
Serial tranceiever
CONFIG.ALIGN
CONFIG.FORMAT
CONFIG.RATIO
RAM
SDOUT
SDIN
SCK
LRCK