whitequark changed the topic of #prjbureau to: Microchip (Atmel) ATF15xx CPLD reverse engineering · code https://github.com/whitequark/prjbureau · docs https://whitequark.github.io/prjbureau/ · logs https://libera.irclog.whitequark.org/prjbureau
<astrobunny> ah yeah for sure
<astrobunny> i realized i messed up the oe mux and i havent drawn the fb mux
<astrobunny> i noticed in the datasheet theres an inverter on the logic foldback
<astrobunny> i guess it nots the logic feedback
<astrobunny> i noticed also that in one of the files produced in the fitter it seems to have sent the dff output to the mc's flb
<astrobunny> i wonder if theres another mux that selects if the y1 or output gets placed on the flb
<astrobunny> because they seem to share that line
<astrobunny> inb4 they are just a dangerous short and its up to the fitter to avoid a situation where they both drive it
<astrobunny> strange thing is the output flb seems to go to the mc flb but the diagram in the datasheet shows it goes to the uim so i am a bit confused there
<astrobunny> tried to poke the fitter to force it to use a logic foldback but it has so far refused my advances
<whitequark> <astrobunny> "strange thing is the output..." <- the diagram in the datasheet is often wrong
<whitequark> <astrobunny> "tried to poke the fitter to..." <- yeah this is really hard
<whitequark> look at the fuzzing scripts for foldback
<whitequark> astrobunny: so, i won't have time in the following days, but i propose we collaborate on this the next Sunday after tomorrow
<astrobunny> no problem next sunday sounds good
<astrobunny> also after spending some time on reading on the train, i realized i was conflating the logic *foldback* and output _feedback_
<astrobunny> turns out Mx_FLB comes from logic and Mx_FB is something the uim can connect to, so the datasheet is okay
<astrobunny> but my diagram isn't
<whitequark> yes
<astrobunny> ill try and make my rats nest more accurate first so i can assure myself i know what is going on. i think i more or less have the pieces i need to write a bit of verilog now
<astrobunny> also it seems the older datasheets have much more info than the new ones
<astrobunny> different model but almost the same device, it might actually be the same. only difference here is a Q input to the XOR, not just the QN
<whitequark> yes the AE ones are v useful
<whitequark> i have them archived toi
<whitequark> s/toi/too/