Modelsim PE vs. Aldec Active-HDL (PE)
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From: d_s_klein on 4 Mar 2010 12:05 On Mar 4, 8:07 am, "cfelton" <cfelton(a)n_o_s_p_a_m.ieee.org> wrote: > BOMK it has been expanded since then. > BOMK?
From: Nick on 4 Mar 2010 12:07 >I've finally decided to buy a better simulator >(I've been making do with Modelsim XE so far). > >Any thoughts as to the relative merits of Modelsim PE and >Active-HDL (PE) for FPGA simulation? > >Thanks > >Pete > > I have been using both Modelsim PE and Active HDL since last six years. over the years , I have seen noticeable speed advantage of 2-3 times in Active HDL-PE compared to Modelsim-PE. I also use lot of scripts to simulate my designs and link files to AHDL without making local copies in AHDL project.Well there is definite cost advantage with active HDL-PE. -Nick --------------------------------------- Posted through http://www.FPGARelated.com
From: Andy Peters on 4 Mar 2010 14:56 On Mar 3, 3:42 pm, d_s_klein <d_s_kl...(a)yahoo.com> wrote: > On Mar 3, 5:02 am, "Pete Fraser" <pfra...(a)covad.net> wrote: > > > I've finally decided to buy a better simulator > > (I've been making do with Modelsim XE so far). > > > Any thoughts as to the relative merits of Modelsim PE and > > Active-HDL (PE) for FPGA simulation? > > > Thanks > > > Pete > > One complaint I have about Active-HDL is that it insists on making a > copy of the sources and hiding them in a not so easy to find > location. It will then simulate these, and only these copies. If you > change a file while simulating, you have to remember to copy it out. > If you change something between simulations, you have to re-import it. > > This "feature" makes the simulator mostly useful only *after* all the > bugs are fixed. (argh) As Rick says, when you choose "Add New File," there is a check-box for "Make Local Copy," which if de-selected seems to get grayed out so you can never select it again. However when this is deselect the project does not copy the file and instead references it from wherever it lives. I find Aldec's forced directory structure to be rather stupid, and it's really difficult to put it reasonably into a source-code control system. It wants to put all of the scripts and configuration files into its src directory, which of course breaks the cardinal rule "don't put synthesizable sources and configuration files in the same directory!" and it's got too many configuration files. ModelSim has one project file (the .mpf) which is plain text and easily edited by hand. I think it's whole notion of workspaces is pretty useless, too. It has a potential to be useful, in that you can put multiple designs in it. Consider, for instance, a design which has a top-level source and three lower-level sources. Of course you want some kind of test bench for each lower-level source, and it would seem that creating a "Design" for each in the workspace would work. But it doesn't. One reason is that each design has a library associated with it (and the default name is NOT work, but rather the design name). You cannot have a library that is shared among all of the designs in a workspace. Also, you can't call the work library for each design "work" -- they have to have different names. This all matters if you are lazy like me and you use direct instantiation of lower-level entities: u_lower : entity work.lower port map (foo => foo, bar => bar); I suppose the "right" thing to do in that case is to create a library for each entity, analyze each into this library and instantiate from it. This all assumes that your synthesis tool can support this. Finally, I really like ModelSim's concept of "simulation configurations." They're very easy -- you create a configuration, tell it the top-level entity, set all of the generics and various other things, and it's done. Click on the simulation configuration and off you go. Sure, these things are nothing more than wrappers around the vsim command but they're very handy. Active-HDL doesn't have this feature, so the workaround is to create tcl scripts which call asim with the proper command line. So, yeah, Active-HDL is fine but if you are used to ModelSim's features it can be confusing. I've spoken to Aldec's support folks about the really fscking stupid forced directory structure, the overabundance of configuration files and the lack of simulation configurations. I don't know whether they will, or even can, change some of this stuff without breaking existing projects, but as a paying customer I guess I'm allowed to make suggestions. -a
From: Andy Peters on 4 Mar 2010 15:10 On Mar 4, 10:05 am, d_s_klein <d_s_kl...(a)yahoo.com> wrote: > On Mar 4, 8:07 am, "cfelton" <cfelton(a)n_o_s_p_a_m.ieee.org> wrote: > > > BOMK it has been expanded since then. > > BOMK? "best of my knowledge." -a
From: Martin Thompson on 5 Mar 2010 05:34
Andy Peters <google(a)latke.net> writes: > ModelSim has one project file (the .mpf) which is plain text and > easily edited by hand. Various others have also mentioned project files and workspaces and the like... Am I the only one that makes *no* use of the various "project things" (either in Modelsim or Aldec)? I just have a makefile and use the GUI to run the sim (from "their" command-line) and show me the waveforms. I guess I don't like to be tied to a tool (as much as I can manage) much as I don't like to be tied to a particular silicon vendor (as much as I can manage :) Am I missing something valuable, or is it just different? Cheers, Martin -- martin.j.thompson(a)trw.com TRW Conekt - Consultancy in Engineering, Knowledge and Technology http://www.conekt.net/electronics.html |