User's Manual

S3C2450X RISC MICROPROCESSOR IIS-BUS INTERFACE
25-1
25 IIS-BUS INTERFACE
1 OVERVIEW
IIS (Inter-IC Sound) is one of the popular digital audio interface. The bus has only to handle audio data, while the
other signals, such as sub-coding and control, are transferred separately. Surely, it is possible to transmit data
between two IIS bus. To minimize the number of pins required and to keep wiring simple, basically, a 3-line serial
bus is used consisting of a line for two time-multiplexed data channels, a word select line and a clock line.
IIS interface transmits or receives sound data from external stereo audio codec. For transmitting and receiving
data, two 32x16 FIFOs (First-In-First-Out) data structures are included and DMA transfer mode for transmitting or
receiving samples can be supported. IIS-specific clock can be supplied from internal system clock controller
through IIS clock divider or direct clock source.
2 FEATURE
• 2-ch IIS-bus for audio interface with DMA-based operation
• Serial, 8/16/24 bit per channel data transfers
• Supports IIS, MSB-justified and LSB-justified data format
• 32-bit width 16depth Tx FIFO, 32-bit width 16depth Rx FIFO
3 SIGNALS
Name Direction Description
I2S1_LRCLK Input/Output IIS-Bus Audio channel select(word select) clock
I2S1_SCLK Input/Output IIS-Bus Audio serial clock(bit clock)
I2S1_CDCLK Input/Output IIS-Bus Audio Codec clock
I2S1_SDI Input IIS-Bus Audio serial data input
I2S1_SDO Output IIS-Bus Audio serial data output