User’s Manual U14272EJ3V0UM
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CHAPTER 15 AUDIO INTERFACE UNIT (AIU)
15.1 General
The AIU controls the analog output (speaker output) processing of the internal D/A converter and the analog input
(microphone input) processing of the internal A/D converter. It is also used to make settings related to the A/D and
D/A converters.
The main functions of the AIU are as follows:
•
Holding the digital value converted by the internal A/D converter
•
Holding the digital value to be converted by the internal D/A converter
•
Separating data being converted by the A/D or D/A converter and transfer data by using double buffers
•
Linking the update of the double buffers and the generation of DMA transfer requests with the data conversion
rate
Caution No clocks are supplied to the AIU, A/D converter, and D/A converter in the initial state. When
using the AIU, set the MSKAIUPCLK, MSKADUPCLK, and MSKADU18M bits of the CMUCLKMSK
register in the MBA Host Bridge to 1 in advance so that clocks are supplied.