What does LRCK stand for?

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jeffythedragonslayer
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What does LRCK stand for?

Post by jeffythedragonslayer »

The acronym LRCK appears in this documentation:

https://problemkaputt.de/fullsnes.htm#s ... iplydivide
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dougeff
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Re: What does LRCK stand for?

Post by dougeff »

Left Right Clock
nesdoug.com -- blog/tutorial on programming for the NES
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jeffythedragonslayer
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Re: What does LRCK stand for?

Post by jeffythedragonslayer »

Oh thanks this makes more sense now:
DATA changes on falling CLK and is valid on raising CLK, falling LRCK indicates that the most recent 16 bits were LEFT data, raising LRCK indicates RIGHT data. Each 16bit sample is preceeded by 8 dummy bits (which are always zero). The 16bit values are signed without BIAS offset (0000h=silence).
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jeffythedragonslayer
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Re: What does LRCK stand for?

Post by jeffythedragonslayer »

What about those 3 MX pins (DSP.Pin3,4,5)? That sounds like the MX pin on the 65816, for accuMulator and indeX. According to the superfamicom wiki, they are not connected:

https://wiki.superfamicom.org/schematic ... pinout-296

The DSP isn't anything like the Ricoh CPU, so idk.
lidnariq
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Re: What does LRCK stand for?

Post by lidnariq »

The DSP-n chips are mask-programmed µPD7725 DSP chips. The datasheet for the programmable version of the same should be mostly accurate.
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jeffythedragonslayer
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Re: What does LRCK stand for?

Post by jeffythedragonslayer »

Oh, sorry, I meant the S-DSP chip that's connected to the SPC700 and ARAM, not the enchantment chip. Those MX signals in fullsnes appear right below the LRCK.
lidnariq
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Re: What does LRCK stand for?

Post by lidnariq »

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jeffythedragonslayer
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Re: What does LRCK stand for?

Post by jeffythedragonslayer »

My guess is X for "access?"
lidnariq
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Re: What does LRCK stand for?

Post by lidnariq »

Not Multiple-X. Multiplex.
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jeffythedragonslayer
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Re: What does LRCK stand for?

Post by jeffythedragonslayer »

Ok.

You know, I think "Stereo Clock" is a much better name than "Left Right Clock."
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TmEE
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Re: What does LRCK stand for?

Post by TmEE »

LRCLK is an established term from the time when CDs became a thing in 80s. The name comes from the fact that each signal edge tells when one channel starts and another ends (and things don't have to be symmetric either and there are hardware where it isn't such as Gravis Ultrasound's GF1 chip and several Roland synth chips). Stereo Clock wouldn't be bad but SCLK is already used up by System Clock in many things but LRCLK has remained available :P
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jeffythedragonslayer
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Re: What does LRCK stand for?

Post by jeffythedragonslayer »

Well, I was thinking more like STECLK.
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