2
Input and Output with the DSK
- Input and output with the onboard AIC23 stereo codec
- Programming examples using C code
2.1 INTRODUCTION
A basic DSP system, suitable for processing audio frequency signals, comprises a digital signal processor and analog interfaces as shown in Figure 2.1. The C6713 and C6416 DSKs provide just such a system, using either the TMS320C6713 (C6713) floating-point processor or the TMS320C6416 (C6416) fixed-point processor and the TLV320AIC23 (AIC23) codec [1]. The term codec refers to the coding of analog waveforms as digital signals and the decoding of digital signals as analog waveforms. The AIC23 codec performs both the analog-to-digital conversion (ADC) and digital-to-analog conversion (DAC) functions shown in Figure 2.1.
Alternatively, I/O daughter cards, plugged into the External Peripheral Interface 80-pin connector J3 on the DSK board can be used for analog input and output. However, the programming examples in this book use only the onboard AIC23 codec.
The programming examples in this chapter will run on either the C6713 or the C6416 DSK but for the most part only the C6713 DSK will be referred to.
Sampling, Reconstruction, and Aliasing
Within digital signal processors, signals are represented as sequences of discrete samples and whenever signals are sampled, the possibility of aliasing arises. Later
in this chapter, the phenomenon of aliasing is explored in some detail. Suffice it to say ...