<Wanda[cis]> okay iCE40MX16K sure is interesting
<Wanda[cis]> apparently it's the thing that SB_MAC16 tiles originally come from; they weren't designed for Ultra*
<Wanda[cis]> and they are... weird. the DSP columns contain 2 normal-seeming PLBs between every pair of DSP tiles.
<Wanda[cis]> and the fucking carry chain goes through both PLBs and DSPs.
<Wanda[cis]> apparently CO was originally just connected to the carry input of the next PLB in chain
<Wanda[cis]> and when they made Ultra, they kind of moved DSPs to the side columns and routed CO via random IPconnect instead?
<Wanda[cis]> probably that's why it's so weird
<Wanda[cis]> also it has 16kbit RAM blocks instead of 4kbit. and hard TMDS receiver blocks.
<Wanda[cis]> also a funny PLL variant that can accept differential clocks?
<Wanda[cis]> also it's incredibly buggy in current icecube; seemingly reasonable netlists involving MX16K-specific features just crash placer or router with assertion failures
<Wanda[cis]> I wonder if they broke that stuff when adding Ultra and hacking SB_MAC16 to work with the new connections; might try a much older icecube if I can find it
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<gatecat[m]> The Ultra IPConnect tiles are just logic tiles with the DSPs or whatever taking their inputs from the LUT inputs and routing their output into the LUTCascade input
<gatecat[m]> Almost like they just patched the GDS or something, the LUT is still there
<gatecat[m]> configured to feed from LUTCascade input to output by the tools
<mupuf> Wanda[cis]: PLL with differential clocks?
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<Wanda[cis]> <mupuf> "Wanda: PLL with differential..." <- PLL primitive that accepts a differential clock from two input pads
<Wanda[cis]> likely because the PLLs are somehow used by the hard TMDS receiver macro, and TMDS involves a differential clock
<mupuf> Oh, that would make sense indeed!
<whitequark[cis]> <Wanda[cis]> "likely because the PLLs are..." <- TMDS transmits data at 7X the clock, doesn't it?
<Wanda[cis]> yeah
<Wanda[cis]> er
<Wanda[cis]> hold on, no
<Wanda[cis]> it's 8b10b encoded; it's 10x the clock
<Wanda[cis]> FPD-link is the 7x one
<whitequark[cis]> oh yeah wrong display standard
<whitequark[cis]> well, samedifference
<Wanda[cis]> ... or 3.5x one actually
<whitequark[cis]> * well, same difference
<whitequark[cis]> 3.5x?
<Wanda[cis]> um
<Wanda[cis]> no
<Wanda[cis]> 7x
<Wanda[cis]> with funny duty cycle
<Wanda[cis]> I got very confused about DDR
<whitequark[cis]> a lot of people these days don't know much about the Deutsche Demokratische Republik
<Wanda[cis]> <Wanda[cis]> "it's 8b10b encoded; it's 10x the..." <- and by "8b10b" I actually mean "an off-brand thing that's kinda like 8b10b but different"
<Wanda[cis]> hmm
<Wanda[cis]> I'd be very interested in obtaining the Silicon Blue ICE Technology Library PDF, version 2.4 or 2.5 specifically
<Wanda[cis]> or maybe Lattice ICE Technology Library, not completely sure if it was before or after the acquisition
<whitequark[cis]> found it
<whitequark[cis]> oh wait, i found 2.3, not 2.4
<whitequark[cis]> any idea which SiliconBlue family was called "Los Angeles"?
<Wanda[cis]> I think just the base ice40 one
<Wanda[cis]> LP/HX
<Wanda[cis]> like, AFAICT it's just the codename for ice40
<Wanda[cis]> ... I should write down all the weird codenames I found somewhere I guess
<Wanda[cis]> what the fuck
<whitequark[cis]> a minecraft mod
<Wanda[cis]> https://gist.github.com/wanda-phi/39865789af30371317f5ee5bd3a105a1 here goes; I'll add to it as I come up across more weird names
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<Wanda[cis]> <Wanda[cis]> "I wonder if they broke that..." <- okay I was wrong about this; icecube2-2012.09SP1 is even more buggy, not less
<Wanda[cis]> <Wanda[cis]> "I'd be very interested in..." <- found it
<Wanda[cis]> it's.... less useful than I hoped
<Wanda[cis]> reading the docs from basically every FPGA vendor that is not xilinx makes me suffer and yearn for xilinx docs
<Wanda[cis]> ... okay I have worked around some iCE40MX16K placer bugs and started hitting router bugs instead
<Wanda[cis]> I think I should just declare these parts to be unusably buggy and move on
<whitequark[cis]> <Wanda[cis]> "found it" <- where?
<Wanda[cis]> in icecube doc/ directory
<Wanda[cis]> specifically, I installed version 2013-08
<Wanda[cis]> (had to binsearch a bit for that)