iverilog/tgt-vvp
Cary R fe72d02cf6 Major rework of the ternary operator elaboration code.
This patch reworks much of the ternary code to short circuit when
possible and supports real values better. It adds a blend operator
for real values that returns 0.0 when the values differ and the value
when they match. This deviates slightly from the standard which
specifies that the value for reals is always 0.0 when the conditional
is 'bx. There are also a couple bug fixes.

These fixes have not been ported to continuous assignments yet.
Ternary operators used at compile time and in procedural assignments
should be complete (short circuit and support real values).
2008-03-08 19:45:13 -08:00
..
.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 Fix user functions with right shift argument. 2008-01-15 21:01:16 -08:00
draw_vpi.c Rework ivl_file_table_* interface and fix most vvp/examples. 2008-01-03 14:13:22 -08:00
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 unsigned bit based power support to normal expressions. 2008-02-05 15:33:51 -08:00
eval_real.c Major rework of the ternary operator elaboration code. 2008-03-08 19:45:13 -08:00
modpath.c modpath nodes need vpi expression handles 2007-11-05 19:59:27 -08:00
vector.c Fix that save expression lookaside always clears cached variable values. 2007-04-01 05:26:17 +00:00
vvp-s.conf.in Generate VVP_EXECUTABLE flag in conf files. 2003-12-07 19:28:43 +00:00
vvp.c Rework ivl_file_table_* interface and fix most vvp/examples. 2008-01-03 14:13:22 -08:00
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 Spelling fixes 2008-01-29 20:24:24 -08:00
vvp_process.c Major rework of the ternary operator elaboration code. 2008-03-08 19:45:13 -08:00
vvp_scope.c Correct format string 2008-02-15 13:26:24 -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.