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Construct delayed assignment as an equivilent block.

This commit is contained in:
steve 1999-07-13 04:08:26 +00:00
parent 6852a62e5a
commit c2c9acdbaf
1 changed files with 43 additions and 20 deletions
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63
elaborate.cc
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT)
#ident "$Id: elaborate.cc,v 1.53 1999/07/12 00:59:36 steve Exp $"
#ident "$Id: elaborate.cc,v 1.54 1999/07/13 04:08:26 steve Exp $"
#endif
/*
@ -1161,30 +1161,50 @@ NetProc* PAssign::elaborate(Design*des, const string&path) const
NetAssign*cur;
/* Rewrite delayed assignments as assignments that are
delayed. This only works if the l-value has no mux
expression. */
if (dex && (mux == 0)) {
string tp = des->local_symbol(path);
unsigned wid = msb - lsb + 1;
cur = new NetAssign(tp, des, wid, rv);
for (unsigned idx = 0 ; idx < wid ; idx += 1)
connect(cur->pin(idx), reg->pin(idx+lsb));
delayed. For example, a = #<d> b; becomes:
cur->set_line(*this);
des->add_node(cur);
NetPDelay*dep = new NetPDelay(dex->as_ulong(), cur);
begin
tmp = b;
#<d> a = tmp;
end
delete dex;
return dep;
}
This rewriting of the expression allows me to not bother to
actually and literally represent the delayed assign in the
netlist. The compound statement is exactly equivilent. */
if (dex) {
delete dex;
cerr << delay()->get_line() << ": Sorry, delay expression "
"(or l-value) too complicated." << endl;
des->errors += 1;
}
string n = des->local_symbol(path);
unsigned wid = msb - lsb + 1;
NetNet*tmp = new NetNet(n, NetNet::REG, wid);
tmp->set_line(*this);
des->add_signal(tmp);
n = des->local_symbol(path);
NetAssign*a1 = new NetAssign(n, des, wid, rv);
a1->set_line(*this);
des->add_node(a1);
for (unsigned idx = 0 ; idx < wid ; idx += 1)
connect(a1->pin(idx), tmp->pin(idx));
n = des->local_symbol(path);
NetESignal*sig = des->get_esignal(tmp);
NetAssign*a2 = new NetAssign(n, des, wid, sig);
a2->set_line(*this);
des->add_node(a2);
for (unsigned idx = 0 ; idx < wid ; idx += 1)
connect(a2->pin(idx), reg->pin(idx+lsb));
NetPDelay*de = new NetPDelay(dex->as_ulong(), a2);
NetBlock*bl = new NetBlock(NetBlock::SEQU);
bl->append(a1);
bl->append(de);
delete dex;
return bl;
}
if (mux == 0) {
unsigned wid = msb - lsb + 1;
@ -1763,6 +1783,9 @@ Design* elaborate(const map<string,Module*>&modules,
/*
* $Log: elaborate.cc,v $
* Revision 1.54 1999/07/13 04:08:26 steve
* Construct delayed assignment as an equivilent block.
*
* Revision 1.53 1999/07/12 00:59:36 steve
* procedural blocking assignment delays.
*