IRC logs for #openrisc Friday, 2015-05-08

--- Log opened Fri May 08 00:00:40 2015
stekernolofk: nope...03:05
stekernI'll ping him again about it03:05
olofkHow do I detect overflow in a signed addition? xor between MSBs?14:02
olofk(with an extra MSB)14:03
olofkI got a for loop in verilog where I set bigassnumber = bigassnumber+smallnumber14:04
stekernolofk: this is how it's done in mor1kx:
daliasolofk, if (bigassnumber > TYPE_MAX-smallnumber) ...14:29
daliasthis is sufficient assuming the values are positive14:29
daliasno idea how to express that in verilog14:30
daliasif you have well-defined overflow semantics like unsigned arithmetic would, then signbit^carrybit should be what you want, i think14:31
olofkdalias: I don't think anyone has ever called verilog well-defined... especially when it comes to arithmetics :)14:34
GeneralStupidstekern: yeah i thought of soumething like that, too... But 8 Mb of RAM is not much for that. I thought of not using a coloured image15:05
GeneralStupidiam not sure what the best solution of this is. Is it a good approach to access the sdram with the mor1k, vga and a coprocessor?15:25
GeneralStupidstekern: is your college's code open source?15:40
stekernGeneralStupid: yes, but I don't think the place where the source was published exists anymore16:43
stekernI can try to see it if I can find it somewhere on my hard-disk16:44
GeneralStupidstekern: that would be great as an template :)19:26
stekernGeneralStupid: I found the report at least, will dig some more for the code.
GeneralStupidstekern: the problem i have, at the moment, what did you did on the microprocessor?19:46
stekernthe microprocessor only interpreted the alarm signal and sent a message over a gsm modem19:46
stekernso not really related to the motion detection19:47
GeneralStupidmy main goal is to show the benefit of softcore + co processors ... so i want both, hardware and software solution. It should show that i can do everything in software and only some little parts in hardware for gaining performance... But just because of the RAM it seems like i have to do the most stuff in hardware and the softcore is more or less unnecessary.19:55
GeneralStupidoh its great: I worked three years as software developer and this is exactly what happened one time to me:
--- Log closed Sat May 09 00:00:41 2015

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