iverilog/tgt-vvp
Stephen Williams ca517b5519 Handle corner cases of abs(), min() and max()
The abs() function needs to be able to turn -0.0 into 0.0. This proved
to be too clunky (and perhaps impossible) to do with tests and jumps,
so add an %abs/wr opcode to do it using fabs().

The min/max functions need to take special care with the handling
of NaN operands. These matter, so generate the extra code to handle
them.
2008-05-06 22:19:59 -07:00
..
.cvsignore vvp.conf files are generated. 2005-03-18 02:57:23 +00:00
Makefile.in Put modpaths in correct scope. 2007-10-31 21:45:34 -07:00
README.txt tgt-vvp generates code that skips nets as inputs. 2001-08-10 00:40:45 +00:00
configure.in Use inttypes.h to get uint64_t print format string 2008-01-14 09:53:20 -08:00
draw_mux.c Support delays for all operators in a continuous assignments. 2008-01-21 18:21:31 -08:00
draw_ufunc.c Detect thread bit allocation failures 2008-04-15 21:51:03 -07:00
draw_vpi.c Detect thread bit allocation failures 2008-04-15 21:51:03 -07:00
eval_bool.c Use inttypes.h to get uint64_t print format string 2008-01-14 09:53:20 -08:00
eval_expr.c Add support for abs() in logic threads. 2008-05-04 22:00:01 -07:00
eval_real.c Handle corner cases of abs(), min() and max() 2008-05-06 22:19:59 -07:00
modpath.c Add ifnone functionality. 2008-04-29 11:55:32 -07:00
vector.c Detect thread bit allocation failures 2008-04-15 21:51:03 -07:00
vvp-s.conf.in Generate VVP_EXECUTABLE flag in conf files. 2003-12-07 19:28:43 +00:00
vvp.c Detect thread bit allocation failures 2008-04-15 21:51:03 -07:00
vvp.conf.in Generate VVP_EXECUTABLE flag in conf files. 2003-12-07 19:28:43 +00:00
vvp_config.h.in Use inttypes.h to get uint64_t print format string 2008-01-14 09:53:20 -08:00
vvp_priv.h Detect thread bit allocation failures 2008-04-15 21:51:03 -07:00
vvp_process.c Add force/release and assign/deassign for real values. 2008-04-17 20:18:20 -07:00
vvp_scope.c Merge branch 'verilog-ams' 2008-05-06 21:00:12 -07:00

README.txt

THE VVP TARGET

SYMBOL NAME CONVENTIONS

There are some naming conventions that the vp target uses for
generating symbol names.

* wires and regs

Nets and variables are named V_<full-name> where <full-name> is the
full hierarchical name of the signal.

* Logic devices

Logic devices (and, or, buf, bufz, etc.) are named L_<full_name>. In
this case the symbol is attached to a functor that is the output of
the logic device.


GENERAL FUNCTOR WEB STRUCTURE

The net of gates, signals and resolvers is formed from the input
design. The basic structure is wrapped around the nexus, which is
represented by the ivl_nexus_t.

Each nexus represents a resolved value. The input of the nexus is fed
by a single driver. If the nexus in the design has multiple drivers,
the drivers are first fed into a resolver (or a tree of resolvers) to
form a single output that is the nexus.

The nexus, then, feeds its output to the inputs of other gates, or to
the .net objects in the design.