The big news is that module instance arrays now work. Gate and UDP
instance arrays have worked for a while, but module instance arrays
were more tricky because of the scope arrys they create. The issues
have been dealt with, and module instance arrays are now supported.
An interesting but subtle set of bugs in the evaluation of ternary
expressions has been fixed. The problems expressed themselves when the
condition expression was constant.
Degenerate wait statements now work properly.
The @* syntax apparently missed sensitivities in l-value expressions
of assignment statements. This led to subtle bugs in carefully crafted
bits of code.
Verilog attributes are properly parsed in a few more contexts. Also,
some specify syntax cases have been fixed.
Some minor spelling and documentation errors have been fixed, along
with assorted compiler warnings.
changes include:
Added support for the `default_nettype directine, including the
default net type of "none", which turns off implicit net declarations.
Signed /, % and >>> in nets should now work properly. Also, various
operators of all sorts applied to constants have been improved.
Ranges now work on localparams.
Added the system tasks $unsigned, $is_signed, $mti_random and
$mti-dist_uniform. See the make README.txt for a description of these
system functions. Also, flesh out the standard random number
generators to match the sequences generated by other compilers.
There is now an "sft" file that describes to the compiler the return
value of system functions. This allows user supplied system functions
to have interesting return types. See "SYSTEM FUNCTIO TABLE FILES" in
the iverilog man page. Include a sft file for the system functions,
and move the system functions over to that mechinism.
Fix the behavior of $fgets in tight fitting result buffers.
A variety of compilation environment fixes have been added. These
involve configure scripts and Makefiles.
And of course a variety of other bug fixes, and so on and so forth.
* Release Notes for Icarus Verilog Snapshot 20040606
Ports of primitives can bind by name as well as by position. Also
support Verilog 2001 style port declarations for primitives.
System function return types can now be specified by system function
table files. System Function Table Files are described in the iverilog
man page. Also include better system function return types in VPI.
Non-blocking assign of real values to real variables now works.
Properly handle nul strings ("") as 8bit values. This is a weirdness
legacy of XL.
Fix some synthesis problems for logical OR and logical AND. Bitwise OR
and AND were fine. These fixes affected simulation as well.
Handle wait statements with all sorts of constant values. These are
sometimes weird, bug legal.
Handle Negative value reals, and a few other bugs related to real
numbers.
Change internal use of identifiers to perm_strings for better
performance.
Functions returning unsupported types now generate error
messages. Previously, they would quietly generate bad
code. Infrastructure is also added to eventually support arbitrary
function return types.
Better compile-time support for Cygwin vs mingw32.
The ipal target is removed from this source. (ipal is now an add-on
package that is compiled seperately.)
There was a couple of snapshots since february; besides bugfixes the
major highligths might be:
-handling of real values at various places
-support for library modules (esp cadence PLI1)
-better FPGA support (esp Virtex II)
-"vvp" interactive mode added
Also converted to buildlink2, and dependencies to libz, libbz2 and
readline added.
This is the first packaged (in pkgsrc) snapshot after the verilog-0.7
release.
This snapshot adds preliminary support for real variables to the language
to the features already found in verilog-0.7.
Release Notes for Icarus Verilog Snapshot 20021019
The synthesizer now detects asynchronous set/reset inputs to DFF
devices. The fpga and vvp code generators have been updated to support
these signals.
The vvp code generator also gained some register management code that
improves the thread register usage. This redoces code size for certain
common cases, and thus improves simulation performance.
The requirements on `ifdef and related compiler directives has been
relaxed, to correspond to more common behavior.
The parameter range support crashed if the range expressions had
parameters in them. This is fixed, and some signed-ness bugs fixed
along with it.
Rearrange some of the configure script tests to assure better
compatibility accross platforms.
Release Notes for Snapshot 20020828
This snapshot adds support for parameter and localparam bit
ranges. This is a IEEE1364-2001 feature, although some -1995 compilers
have supported it in the past.
Fixed a *nasty* and slippery bug with the evaluation of bit select of
nets. (Bit select of variables was unaffected.) The symptoms did not
clearly point to the problem, so bugs related to it were often mis-
reported.
Gate delays were lost when constants were propagated to their
inputs. This is fixed for the known broken cases. Also, mux output
delays have been fixed. Also, release statements that apply to elided
nets are turned into no-ops.
The r-values of non-blocking assignments are now precalculated at
compile time, if possible, as is done with blocking assignments. This
speeds up constant propagation, and is more thorough.
Also optimize subtraction of small constants from vectors, with the
new %subi instruction in vvp. This saves some in code size and thread
footprint.
Handling of x in r-value bit selects and memory word selects did the
wrong thing. Now they do the right thing. Also, x in the selector of
?: ternary operators does the right (and complicated) thing now. In
the process, a fork-join code generator bug was fixed.
Several bugs with time formatting have been fixed.
Temporaries in sequential blocks are detected by the synthesizer, and
converted into wires when needed. This expands support for
combinational logic synthesis.
many improvements and bug fixes since the last packaged snapshot including:
-added the $sizeof system function as a builtin
-In VPI, the simulator event callbacks now work
-Concatenation expressions in parameters were broken are broken
-added the vpiModule iterator to VPI scope handles
Release Notes for snapshot 20020317
The first difference in this snapshot from the 0.6 release is that vvm
is no longer compiled by default. If you want to compile vvm, you must
enable it at configure time (--enable-vvm) and rebuild from
scratch. Eventually, vvm will disappear from the release altogether.
The next major difference is new support for user defined
functions. It is new support, so it is bound to be buggy, but it
should be somewhat complete. The major problem has been solved, so all
that remains are bugs around the edges.
The vvp run-time scheduler has been changed slightly. The run time
behavior is getting increasingly precise and picky, as larger designs
are thrown at the compiler. The change introduced in this snapshot
fixes logic gates to not propagate zero-time pulses, and thus fixes
some weird bugs in large designs.
I've also added initial support for the Verilog 200x pragma comment,
which are (* *) pairs. For now, the compiler ignores them as
comments. This is what a compiler is supposed to do with anything that
is not specifically recognized.
Also, Tony (Anthony Bybell) has added LXT dump support. The LXT output
file is a waveform output format that is much more compact then VCD.
The gtkwave waveform viewer supports the LXT format, and should
operate a bit faster when viewing LXT files. For now, there are
separate system tasks for managing LXT output ($lxt_dumpvars, etc) but
eventually the dump format will be selectable by environment variable
or command line switch.
This snapshot also includes various random bug fixes and improved
error messages for incorrect code.
many many changes since the last packaged snapshot.
A brief sampling of the changes (which include many bug fixes and
enhancements) is:
A variety of little problems with $display format strings have been
fixed.
The % operand should now simulate properly. Also, the * operator is a
little bit more optimized, and works in constant expressions.
Several bugs in strength modeling have been fixed. This includes drive
strengths on continuous assignments, which in the past generated code
without the strengths. Also, vvp gained some missing support for
constants with strength. I think that strength modeling is now
complete.
vpi_get_vlog_info support has been added to the vvp run-time. This is
a PLI function that allows access to run-time command flags. Also, vpi
access to root modules now works properly.
Many changes since the last packaged snapshot. A sampling of these are:
Support for hierarchical names has been largely rewritten. The major
consequence of this is that escaped names now have much better
support. By now, most any combination of escaped and hierarchical name
should work properly, for nets, parameters, and anything else.
Output delays for primitive gates, including user defined primitivies,
should now work properly. Delays on nets still do not work, although
the parser now parses them and prints a "sorry" message.
Bugs in support for division(/) and modulus (%) have been fixed.
Bugs in l-values of synthesized DFF devices have been fixed. These
bugs were related to part selects of vectors in l-values.
A few XNF code generator bugs and limitations were fixed.
And as usual, a variety of miscellaneous bugs have been fixed in this
snapshot.
The bit size of the results of some unary redunction operators is now
properly handled. Also, similar problems with logical functions have
been fixed.
force/release now works for variables, though not yet for
nets. Assign/deassign already work.
many other bugfixes
changes since last snapshot include:
- addition of a fpga target for synthesis. outputs edif, optimized for
xilinx virtex parts.
- fixed bug with synthesis of !=
- fixed bug in hex constant parsing
- fixed vvp bug with subtracting very wide words
- much improved VCD output
- many other bug fixes and robustness improvements.
changes are:
-----------
RELEASE NOTE FOR ICARUS VERILOG 20010630
I've done some cleanup of the mingw port of Icarus Verilog. I've also
added instructions for how to build Icarus Verilog under mingw. I'm
working on making that the preferred way to support Windows, and when
I make the 0.5 release I will make Windows binaries this way. Anyhow,
feedback on the build instructions and the build results using the
instructions in mingw.txt are welcome.
I've make "vvp" the default target type. The older vvm behavior is
available with the "-tvvm" flag to iverilog, but I would rather be
told about (and fix) bugs in the vvp code generator and run time.
I've added support for the (unsigned) right shift operator. The left
shift has been working for a while now, but right shift somehow
slipped through the cracks. The shift operators still don't quite work
in structural contexts, but they should show up sometime next week.
I've finally got VCD output working properly with vvp. It may even be
better then with vvm, although some internal symbols are still generated.
A few odd bugs have been fixed, including a code generation error for
xnf, and error checking of user defined function parameters.
many changes since the last snapshot. Mostly they involve expanded
VVP support. The VVP target now passes >200 of the tests from the
test suite. While not as complete as the VVM target, VVP is getting
closer and its _much_ _much_ faster.
