7.1.6 OUTLINE OF THE WAVEFORMS RECEIVED BY THE DSP SECTION
A
The illustrated signal waveform is an example of the signal waveform when a Dolby Digital (Fs = 48 kHz) signal is received. It must be noted that a frequency (waveform period) other than that of the Master clock supplied to the DSP section changes depending on the format of input signals or mode of the unit. It must also be noted that the waveform being observed changes depending on the environment of the measurement system (high-frequency characteristics of an oscilloscope or a probe, grounding method, etc.). (The numbers 1-9 of the waveform names correspond to those of the waveform data and those in the clock flowchart.)
S/PDIF signal waveforms
� Flow indicated with " " in the clock flowchart Aperiodic rectangular-wave signal 1 COAXIAL or demodulator input: Amplitude of approx. 5 Vp-p (when the signal is input to IC101) 2 OPTICAL input: Amplitude of approx. 4 Vp-p (when the signal is input to IC101) 3 OPTICAL output: Amplitude of approx. 3.3 Vp-p (when the signal is output from IC101) In the following waveforms, the amplitude of all clocks is approx. 3.3 Vp-p.
B
Audio data waveform
� Flow indicated with " " in the clock flowchart Aperiodic rectangular-wave signal 4 Audio data waveform
Audio bit clock waveform
C
� Flow indicated with " " in the clock flowchart Aperiodic rectangular-wave signal 5 Bit clock waveform
Audio L/R clock waveform
� Flow indicated with " " in the clock flowchart Aperiodic rectangular-wave signal 6 L/R clock waveform (except 2nd DPS) Waveforms of the lines other than those supplied to the second DSP 7 L/R clock waveform (2nd DPS) Waveforms generated in the block that supplies signals to the second DSP
Audio master clock waveform
D
� Flow indicated with " " in the clock flowchart Aperiodic rectangular-wave signal 8 Master clock waveform (for Audio signal)
DSP master clock waveform
� Flow indicated with " " in the clock flowchart Aperiodic rectangular-wave signal 9 Master clock waveform (for DSP) Only this clock operates on a fixed frequency: 12.5 MHz (80 ns).
