Commit Graph

20 Commits

Author SHA1 Message Date
Cary R bc8704e47d Translate a BUFT device correctly in VHDL back end
When the BUFT device was added to the compiler nothing was done to
support it in the VHDL translator. This patch rectifies that oversight.
2011-06-26 11:20:54 -07:00
Stephen Williams ec49f10e2d Revert bad merge from vhdl branch 2010-10-02 11:02:27 -07:00
Nick Gasson 9c568d8f47 VHDL: ensure with-select statement choices completely cover input space
Newer versions of GHDL seem to be stricter when checking this than
older versions. ModelSim still accepts an incomplete with-select,
however.

This patch makes the output 'U' if none of the conditions match.
2009-12-14 12:01:27 -08:00
Nick Gasson ee5302cf33 Fix some more errors when reading from VHDL outputs
I forgot to modify the LPM generating code with the
last patch. This *should* now always ensure a signal
is readable before code is generated to read from it.
2009-01-25 07:50:03 -08:00
Nick Gasson 69e91e4065 Fix various problems with VHDL `buffer' port generation
This patch corrects several bugs with the generation of
VHDL `buffer' ports. The code generator should now
generate a buffer only if the port needs to be read inside
the architecture, otherwise it will stay `out'.

This also correct a bug where an output port is connected
directly to the output of an instantiated component. Generating
`buffer's would work here, but a more idiomatic VHDL approach is
to declare an intermediate signal which both outputs are connected
to. This is implemented in the patch (fixes the regression of
readout.v in the testsuite).
2009-01-25 07:49:54 -08:00
Nick Gasson f1f9274bb9 Move VHDL global state management to a single file
The new state.cc/hh file now manages all the global
state that we maintain while generating VHDL. This
should make the code a bit tidier.
2009-01-17 09:19:58 -08:00
Larry Doolittle f233793061 Spelling fixes
No code changes.
2008-09-09 19:21:42 -07:00
Nick Gasson e1deba51ab Handle BUFIF logic when vector inputs 2008-08-18 15:48:07 +01:00
Nick Gasson a577ee447b Generate process for sequential UDPs 2008-08-13 17:03:03 +01:00
Nick Gasson d7b85c42a0 Split sequential and combinatorial UDPs into separate functions 2008-08-13 11:57:05 +01:00
Nick Gasson a3929330b0 Fix regression caused by UDP delay patch
translate_time_expr cannot be passed a NULL ivl_expr_t.
2008-08-11 20:53:13 +01:00
Nick Gasson 9b1f2d5971 Remove UDP debug messages from output 2008-08-11 20:37:10 +01:00
Nick Gasson 9d7e4ac15f Allow delays in combinatorial UDPs
Add a `after' clause to the `with .. select' statement.
2008-08-11 20:36:09 +01:00
Nick Gasson 01bf741983 Implement combinatorial UDPs
Using a `with .. select' statement
2008-08-11 13:23:50 +01:00
Nick Gasson 6dcf936807 Generate combined input for UDP devices
Combinatorial UDPs will be implemented with a `with ... select'
statemetnt. However the input to this must be "locally static".
This patch joins the inputs into a vector which can be used as
the select expression.
2008-08-11 12:58:46 +01:00
Nick Gasson c849dfeec4 Add XNOR logic device 2008-08-05 10:45:01 +01:00
Nick Gasson e0834f7f38 Add NAND and NOR logic devices 2008-08-01 17:46:04 +01:00
Nick Gasson 7b0f675785 Add check for sequential UDPs 2008-07-31 21:08:59 +01:00
Nick Gasson db339b8fc3 Stub for UDP logic devices 2008-07-31 20:59:20 +01:00
Nick Gasson baa2363e85 Split logic device code into separate file 2008-07-30 10:13:08 +01:00