iverilog/tgt-vvp
Stephen Williams f5728c4a39 Add appropriate hysteresis to tranif input pins.
The tranif input pins are normally nothing special, but sometimes
they are fed back from the switch body. In this case, the control
needs to see the current *output* from the fed back port, in order
to get the results that people expect.
(cherry picked from commit 33158355ba)

Conflicts:

	tgt-vvp/draw_net_input.c
	vvp/island_tran.cc
2009-10-28 16:32:40 -07:00
..
Makefile.in Still more build system cleanup. 2009-10-26 11:12:04 -07:00
README.txt tgt-vvp generates code that skips nets as inputs. 2001-08-10 00:40:45 +00:00
draw_mux.c Add error message that only 32 bit immediate CA delays are supported. 2009-10-26 11:14:19 -07:00
draw_net_input.c Add appropriate hysteresis to tranif input pins. 2009-10-28 16:32:40 -07:00
draw_switch.c Content-free portability fixes. 2008-09-29 18:06:47 -07:00
draw_ufunc.c Content-free portability fixes. 2008-09-29 18:06:47 -07:00
draw_vpi.c Warn that &A<> may have problems with a signed select from thread space. 2009-09-24 12:16:54 -07:00
eval_bool.c Add support for 64 bit delays in procedural non-blocking assignments. 2009-02-17 10:32:11 -08:00
eval_expr.c Add file/line information to named events and better expr. error. 2009-09-13 08:34:59 -07:00
eval_real.c For real expressions evaluate non-real sub-exprs as bits and convert. 2009-06-23 09:37:41 -07:00
modpath.c Content-free portability fixes. 2008-09-29 18:06:47 -07:00
vector.c Remove most of the lingering CVS droppings. 2008-12-05 21:48:28 -08:00
vvp-s.conf.in Remove redundant back-end selections. 2008-09-07 16:43:54 -07:00
vvp.c Some compiler cleanup and minor memory leak fixes. 2009-06-23 09:14:03 -07:00
vvp.conf.in Remove redundant back-end selections. 2008-09-07 16:43:54 -07:00
vvp_config.h.in Remove most of the lingering CVS droppings. 2008-12-05 21:48:28 -08:00
vvp_priv.h Some compiler cleanup and minor memory leak fixes. 2009-06-23 09:14:03 -07:00
vvp_process.c Optimize a full L-value indexed part select, etc. 2009-09-24 13:32:57 -07:00
vvp_scope.c Add error message that only 32 bit immediate CA delays are supported. 2009-10-26 11:14:19 -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.