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Re: Thanks for the explanation

<< Is the Pioneer MPEG decoder also clocked from a derivative of your master clock? >>

Yep.

In this particular case, there are about 5 different frequencies fed to the MPEG decoder. Some are based on 27 MHz (video stuff), some on multiples of 44.1 kHz (for CD stuff), some on multiples of 48 kHz (for DVD stuff), and some that change depending on whether you are playing a CD or a DVD.

Normally these clocks are all generated by a 3-PLL chip that is driven by a 27 MHz crystal oscillator. We remove the crystal and inject our own 27 MHz signal that is derived from our audio master clock by a second custom-programmed PLL that we add. The "N" and "M" divide ratios in the second PLL are controlled by the same flag that tells whether to use the 44.1 kHz based audio clock or the 48 kHz based audio clock. So when we change audio clocks, the second PLL just keeps outputting the 27 MHz to the PLL for the Pioneer MPEG decoder. Everything always stays synched up, but is governed by the audio master clock.

The details are different, but a similar implementation is used in our D-1xe and DX-7e DVD players. The audio clock is the master, and everything else is slaved to that.

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