A non-blocking event controlled assignment consists of 3 steps.
* Setup event
* Perform assignment
* Clear event
This works fine if the lvalue is a singular value. If the lvalue is a
concatenation multiple assignments are generated and the event is cleared
after each assignment. As a result only the first assignment is event
controlled. All other assignments will be regular non-blocking assignments.
E.g.
```
reg x, y;
event e;
{x,y} <= @e 2'b11;
$display(x, y); // x will be 1'b1, y will be 1'bx
```
To resolve this the event needs to be cleared after all assignments have
been done. This requires changes to both tgt-vvp and the vvp runtime.
tgt-vvp is updated to only insert a single `%evctl/c` instruction for each
event controlled non-blocking assignment.
The vvp runtime is not updated to implicitly clear the event in the
`%assign/vec4/e` instruction and instead rely on the explicit `%evctl/c`.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
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|---|---|---|
| .. | ||
| COPYING.lesser | ||
| Makefile.in | ||
| README.txt | ||
| cppcheck.sup | ||
| draw_class.c | ||
| draw_delay.c | ||
| draw_enum.c | ||
| draw_mux.c | ||
| draw_net_input.c | ||
| draw_substitute.c | ||
| draw_switch.c | ||
| draw_ufunc.c | ||
| draw_vpi.c | ||
| eval_condit.c | ||
| eval_expr.c | ||
| eval_object.c | ||
| eval_real.c | ||
| eval_string.c | ||
| eval_vec4.c | ||
| modpath.c | ||
| stmt_assign.c | ||
| vvp-s.conf.in | ||
| vvp.c | ||
| vvp.conf.in | ||
| vvp_config.h.in | ||
| vvp_priv.h | ||
| vvp_process.c | ||
| vvp_scope.c | ||
README.txt
THE VVP TARGET SYMBOL NAME CONVENTIONS There are some naming conventions that the vvp 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.