1. INTRODUCTION ...................................................................................................…. 51.1 General Information ....................................................................................… 52. SYSTEM STARTUP ..............................................................................................…. 62.1 General Purpose I/O Pins and I/O Expander Pins ....................................… 82.1.1 No Digital I/O Configuration .................................................................… 92.1.1.1 Functions within “No Digital I/O Configuration” – mode ……….. 92.1.2 Four-pins Digital I/O configurations ......................................................… 132.1.2.1 Functions within “Four-pins I/O Configuration” – mode ……….. 132.1.3 Six-pins Digital I/O configurations ........................................................… 142.1.3.1 Functions within “Six-pins I/O Configuration” – mode ……..…… 152.1.4 Diode Selection ...................................................................................…. 162.2 Additional External Circuitry .....................................................................…. 182.2.1 Oscillator Circuit .................................................................................…. 182.2.2 Coils at the input of the USB-bus ......................................................….. 192.2.3 Coils at the Vdd lines of the UDA1335H ..........................................…… 192.2.4 I/O expander test – board ……………………………..……………………. 192.2.5 Bilateral Selector / Switch (HEF4066 or 74LV4066) ..………….………... 202.2.6 Single Master Controller board ………………………..……………………. 212.3 Currently implemented hardware configurations ……………………………. 223. CONFIGURATION DATA STRUCTURE ...................................................…… 233.1 Working with Dynamic Bass Boost (DBB) ..........................................…….. 233.2 Working with Default Volume .............................................................……… 233.3 Working with Clipping Prevention and Distortion Level ..................…….. 233.4 Product ID (idProduct) and Vendor ID (idVendor) ............................…..…. 243.5 Other possible hardware configurations ............................……..…………. 244. CUSTOMIZING YOUR DESIGN .................................................................…. 254.1 Handling Device Configurations .......................................................………. 254.2 Configuring the USB-APRP ………...........................................................…. 254.3 The USB-I²C communication driver .....................................................……. 255. USB CONTACT ADDRESS .........................................................................… 266. GLOSSARY ...............................................................................................…... 267. FREQUENTLY ASKED QUESTIONS ........................................................….. 278. REFERENCES .............................................................................................…. 40