SoCKit User Manual
54
www.terasic.com
December 1, 2015
Figure 5-1 Man-Machine Interface of Audio Recorder and Player
Figure 5-2
shows the block diagram of the Audio Recorder and Player design. There are hardware
and software parts in the block diagram. The software part stores the Nios II program in the on-chip
memory. The software part is built by Eclipse in C programming language. The hardware part is
built by Qsys under Quartus II. The hardware part includes all the other blocks. The “AUDIO
Controller” is a user-defined Qsys component. It is designed to send audio data to the audio chip or
receive audio data from the audio chip.
The audio chip is programmed through I2C protocol which is implemented in C code. The I2C pins
from audio chip are connected to Qsys System Interconnect Fabric through PIO controllers. In this
example, the audio chip is configured in Master Mode. The audio interface is configured as I2S and
16-bit mode. 18.432MHz clock generated by the PLL is connected to the MCLK/XTI pin of the
audio chip through the AUDIO Controller.
