iverilog/tgt-vvp
Martin Whitaker 39ee49b252 Improved behaviour of tranif when control is 'x' or 'z'.
The IEEE standard does not specify the behaviour of a tranif primitive
when its control input is an 'x' or 'z'. vvp currently treats these as
if the tran was turned off, but it would be better to propagate the
uncertainty to the tran bi-directional ports. For compatibility with
other simulators, we adopt the behaviour specified for MOS primitives.
2012-04-27 17:08:38 -07:00
..
Makefile.in Update the Makefiles to use more override able values. 2012-01-02 10:27:38 -08:00
README.txt tgt-vvp generates code that skips nets as inputs. 2001-08-10 00:40:45 +00:00
draw_enum.c Add more support for signed enumerations in SV. 2011-09-25 09:56:02 -07:00
draw_mux.c Revert bad merge from vhdl branch 2010-10-02 11:02:27 -07:00
draw_net_input.c Improved behaviour of tranif when control is 'x' or 'z'. 2012-04-27 17:08:38 -07:00
draw_switch.c Fix for pr3499807. 2012-03-12 09:03:53 -07:00
draw_ufunc.c Add support for tracing procedural statements. 2011-03-01 18:45:29 -08:00
draw_vpi.c Better VPI reference to part of array word. 2012-01-10 18:22:52 -08:00
eval_bool.c Add support for tracing procedural statements. 2011-03-01 18:45:29 -08:00
eval_expr.c Remove some MinGW32-w64 compile warnings. 2012-01-05 17:26:08 -08:00
eval_real.c Remove some MinGW32-w64 compile warnings. 2012-01-05 17:26:08 -08:00
modpath.c Make ivl_alloc.h the last include so it doesn't effect any system includes. 2010-11-02 10:51:57 -07:00
stmt_assign.c Fix compressed assign to memory word. 2011-12-18 17:56:41 -08:00
vector.c Fix shadow warnings found on OpenBSD. 2010-05-28 07:03:02 -07:00
vvp-s.conf.in Remove redundant back-end selections. 2008-09-07 16:43:54 -07:00
vvp.c Remove some cppcheck warnings. 2011-05-07 11:40:16 -07:00
vvp.conf.in Remove redundant back-end selections. 2008-09-07 16:43:54 -07:00
vvp_config.h.in Remove malloc.h support and for C++ files use <c...> include files. 2010-06-01 08:56:30 -07:00
vvp_priv.h Rework vvp code generator for compressed assignments 2011-11-28 15:29:53 -08:00
vvp_process.c Rework vvp code generator for compressed assignments 2011-11-28 15:29:53 -08:00
vvp_scope.c Handle l-value part select of packed arrays. 2012-02-10 18:48:12 -08:00

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.