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Clean up the edge detector code a bit

This commit is contained in:
Nick Gasson 2008-06-13 12:52:20 +01:00
parent 005df31a0d
commit 70db096b6d
1 changed files with 35 additions and 40 deletions
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75
tgt-vhdl/stmt.cc
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@ -250,6 +250,35 @@ static int draw_delay(vhdl_process *proc, stmt_container *container,
return 0;
}
/*
* Make edge detectors from the signals in `nexus' and add them
* to the expression `test'. Also adds the signals to the process
* sensitivity list. Type should be one of `rising_edge' or
* `falling_edge'.
*/
static void edge_detector(ivl_nexus_t nexus, vhdl_process *proc,
vhdl_binop_expr *test, const char *type)
{
int nptrs = ivl_nexus_ptrs(nexus);
for (int j = 0; j < nptrs; j++) {
ivl_nexus_ptr_t nexus_ptr = ivl_nexus_ptr(nexus, j);
ivl_signal_t sig;
if ((sig = ivl_nexus_ptr_sig(nexus_ptr))) {
const char *signame = get_renamed_signal(sig).c_str();
vhdl_fcall *detect
= new vhdl_fcall(type, vhdl_type::boolean());
detect->add_expr
(new vhdl_var_ref(signame, vhdl_type::std_logic()));
test->add_expr(detect);
proc->add_sensitivity(signame);
break;
}
}
}
/*
* A wait statement waits for a level change on a @(..) list of
* signals.
@ -301,47 +330,13 @@ static int draw_wait(vhdl_process *proc, stmt_container *container,
new vhdl_binop_expr(VHDL_BINOP_OR, vhdl_type::boolean());
// Generate falling_edge(..) calls for each negedge event
for (int i = 0; i < nneg; i++) {
ivl_nexus_t nexus = ivl_event_neg(event, i);
int nptrs = ivl_nexus_ptrs(nexus);
for (int j = 0; j < nptrs; j++) {
ivl_nexus_ptr_t nexus_ptr = ivl_nexus_ptr(nexus, j);
ivl_signal_t sig;
if ((sig = ivl_nexus_ptr_sig(nexus_ptr))) {
vhdl_fcall *detect
= new vhdl_fcall("falling_edge", vhdl_type::boolean());
detect->add_expr
(new vhdl_var_ref(ivl_signal_basename(sig),
vhdl_type::std_logic()));
test->add_expr(detect);
break;
}
}
}
for (int i = 0; i < nneg; i++)
edge_detector(ivl_event_neg(event, i), proc, test, "falling_edge");
// Generate rising_edge(..) calls for each posedge event
for (int i = 0; i < npos; i++) {
ivl_nexus_t nexus = ivl_event_pos(event, i);
int nptrs = ivl_nexus_ptrs(nexus);
for (int j = 0; j < nptrs; j++) {
ivl_nexus_ptr_t nexus_ptr = ivl_nexus_ptr(nexus, j);
ivl_signal_t sig;
if ((sig = ivl_nexus_ptr_sig(nexus_ptr))) {
vhdl_fcall *detect
= new vhdl_fcall("rising_edge", vhdl_type::boolean());
detect->add_expr
(new vhdl_var_ref(ivl_signal_basename(sig),
vhdl_type::std_logic()));
test->add_expr(detect);
break;
}
}
}
for (int i = 0; i < npos; i++)
edge_detector(ivl_event_pos(event, i), proc, test, "rising_edge");
// Add Name'Event terms for each non-edge-triggered signal
string_list_t::iterator it;
for (it = non_edges.begin(); it != non_edges.end(); ++it) {