Tom Hawkins wrote: | I'm almost finished with my Icarus code generator. Just two more | questions: | | For synthesizable targets, how can the code generator determine if the | clock or asynchronous reset for an LPM_FF is sensitive on the positive | or negative edge? I tried a negedge FF, expecting to see a NOT gate | dropped into the final netlist, but no such luck.
Any hints for detecting posedge or negedge? This is my biggest roadblock at this point.
| | Also, are there any assertion capabilities built into Icarus? I'm not | sure if there is anything defined in the 2001 spec -- an $assert, maybe? | Ideally what I need is an IVL_LPM_ASSERT block that has similar | semantics as IVL_LPM_FF, except without the output data (q).
Nothing of the sort, sorry. Actually, assertions would be somewhat similar (in mechinism, if not appearence) to constraints in specify blocks.
Maybe I can get by with some sort of user defined primitive or system task. However, it's not real a high priority item at this point.
| In case my posts haven't given it away, I'm working on a formal | verification plug-in.
You're going to be angry:-O but it is looking like post-0.8 the ivl_target API is going to change some. I'm going to be collapsing arrays of pins down to single pins that carry vector data. I'm looking towards considerably reducing the size of the netlist represented by ivl_target structures, and also allowing pins to carry arbitrary data types.
On the contrary, I'm glad to hear this. Would you consider outside input?
Bill and I have been pondering over an netlist format that could serve as the glue between the various open-source tools. This info is a bit dated -- some of my opinions have changed since I wrote this -- but here's the general gist:
http://www.confluent.org/wiki/doku.php?id=fnf:main
Everything is open to consideration at this point.
-Tom
-- Steve Williams "The woods are lovely, dark and deep. steve at icarus.com But I have promises to keep, http://www.icarus.com and lines to code before I sleep, http://www.picturel.com And lines to code before I sleep."
