We have this homework assignment in Digital Design, another multi-hour engineering problem: design an 8-bit ripple-carry adder. The problem with the problem, as it were, is not with the design of the 8-bit adder. We've done little adders in vhdl before and I just used one of those, modified slightly to meet the specification we were given, because why write code when you can copy/paste? I got that done on Sunday. The problem is that we're using two different sets of tools (software packages) to translate the adder code into actual hardware, analyzing the gate delays, and then abusing our little adder with operations that will strain the timing constraints of the hardware. In English: We make it do hard math that takes a long time to see how long it really takes. Anyway, that isn't even the problem. The problem is that the tools are buggy! Yes, buggy! Buggy in the really charming "that only works if you compile at the command line because if you compile in the GUI you get an error" kind of way. Buggy in the "the signal names get changed in the timing constraints file so you have to go in and edit them by hand to match the post-synthesis structure file" way. So, between the bugs and my lack of familiarity with the software, I spent the day (yes, the whole day) synthesizing and simulating the adder over and over and asking the professor for help interpreting the mysterious error messages. I've barely gotten to the adder-abuse part.
The scary thing is that I'm the only one in the class who's started. It's due Thursday.
273 words | February 7, 2005 10:47 PM | Ivory towerAre these programs open source? Open source means you can waste infinite time fixing something that was never intended to work.
Posted by: Derek at February 12, 2005 05:11 AMNo, they aren't open source. I think that the bugs are overlooked since the tools are designed to synthesize VHDL to specific types of hardware that will rapidly become obsolete.
Posted by: Nee-chama at February 13, 2005 07:44 PM