Post B6PRWxKDZb4SBDLYVk by azonenberg@ioc.exchange
 (DIR) More posts by azonenberg@ioc.exchange
 (DIR) Post #B6PONJJQfd0Rc7geDQ by dlharmon@chaos.social
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       Back to working on the BSDL parser which is turning out to be a bigger project than I originally anticipated. So many corner cases due to the fact that it's VHDL based and the standard allows a lot of variation. Quite a bit of code for port vectors which are only used by 3 of the ~3100 BSDLs I'm testing on. Those 3 are ancient, from 1994-2000 era parts.Maybe I shouldn't be going for completeness.There's a pretty small subset of BSDL used by vendors today.
       
 (DIR) Post #B6PONJibA38gsBSkRk by dlharmon@chaos.social
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       I'm also a bit surprised by a few things in the BSDLs. The TAP_SCAN_CLOCK of many Xilinx parts doesn't correspond to the datasheet Ftck max. XCVU parts have 66 MHz in the BSDLs, datasheet says 20 MHz for all but a few that only have one SLR. XCZU is 30 MHz in the BSDLs, 15 or 25 MHz in the datasheets depending on speed grade. XC6 goes the other way with much lower frequencies in the BSDLs than datasheets.Annoying because I'd hoped to automate selection of a lower TCK if required based on that.
       
 (DIR) Post #B6PONK3rsy9Xw9PjbE by dlharmon@chaos.social
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       Some of the older Xilinx BSDLs are unusual. Here we have don't care bits in most of the IDCODE including all of the manufacturer bits of an old Coolrunner CPLD. Some of the earliest Xilinx parts with JTAG don't even have an IDCODE.I validate the IDCODE register for compliance, these fail as X is interpreted as 0 for that check. Maybe I'll pull that out or maybe just delete these few files.
       
 (DIR) Post #B6PONKQuVIaJ5cC8W0 by azonenberg@ioc.exchange
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       @dlharmon I suspect this is because the CoolRunner family was originally made by Philips and later by Xilinx, perhaps there was a vendor ID change at some point during a metal spin to fix other bugs?
       
 (DIR) Post #B6PORatlECWhJXiu8W by dlharmon@chaos.social
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       @azonenberg Interesting. I didn't know that. Almost curious enough to get a chip and see what it spits out.
       
 (DIR) Post #B6POZZAVXlRsGXMFpA by azonenberg@ioc.exchange
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       @dlharmon (When I say "made" I mean Xilinx acquired the product line, similar to SiliconBlue and Lattice. Not that they switched foundries)
       
 (DIR) Post #B6PRAnGqH5xocrCSUS by azonenberg@ioc.exchange
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       @dlharmon on that note i have an ebay'd alleged SystemACE that I bought to decap, but i want to solder it to a breakout and verify the IDCODE is right beforehand since it looks a little funny.I mean it's getting decapped regardless but i want to have some level of confidence whether it's a fake or not
       
 (DIR) Post #B6PRWxKDZb4SBDLYVk by azonenberg@ioc.exchange
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       @dlharmon I did some quick multimeter checks and it seems to have power and ground pins in the right spots but the laser engraving seems off... i wonder if it's legit silicon but the reseller post-dated it to make it seem like it wasn't 20 year old inventory, not realizing that that actually makes it seem more fishy since it's a legacy part