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Better synthesys of DFF w/ complex l-values. (Larry Doolittle)

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steve 2001-11-30 01:22:21 +00:00
parent 65f835f3eb
commit 0cebef872a
1 changed files with 49 additions and 34 deletions
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83
syn-rules.y
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@ -19,7 +19,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/ */
#if !defined(WINNT) && !defined(macintosh) #if !defined(WINNT) && !defined(macintosh)
#ident "$Id: syn-rules.y,v 1.16 2001/11/29 01:58:18 steve Exp $" #ident "$Id: syn-rules.y,v 1.17 2001/11/30 01:22:21 steve Exp $"
#endif #endif
# include "config.h" # include "config.h"
@ -27,11 +27,11 @@
# include <iostream> # include <iostream>
/* /*
* This file implements synthesys based on matching threads and * This file implements synthesis based on matching threads and
* converting them to equivilent devices. The trick here is that the * converting them to equivalent devices. The trick here is that the
* proc_match_t functor can be used to scan a process and generate a * proc_match_t functor can be used to scan a process and generate a
* string of tokens. That string of tokens can then be matched by the * string of tokens. That string of tokens can then be matched by the
* rules to determin what kind of device is to be made. * rules to determine what kind of device is to be made.
*/ */
# include "netlist.h" # include "netlist.h"
@ -134,6 +134,34 @@ start
/* Various actions. */ /* Various actions. */
static void hookup_DFF_CE(NetFF*ff, NetESignal*d, NetEvProbe*pclk,
NetNet*ce, NetAssign_*a, unsigned rval_pinoffset)
{
// a->sig() is a *NetNet, which doesn't have the loff_ and
// lwid_ context. Add the correction for loff_ ourselves.
// This extra calculation allows for assignments like:
// lval[7:1] <= foo;
// where lval is really a "reg [7:0]". In other words, part
// selects in the l-value are handled by loff and the lwidth().
int loff = a->get_loff();
for (unsigned idx = 0 ; idx < ff->width() ; idx += 1) {
connect(ff->pin_Data(idx), d->bit(idx+rval_pinoffset));
connect(ff->pin_Q(idx), a->sig()->pin(idx+loff));
}
connect(ff->pin_Clock(), pclk->pin(0));
if (ce) connect(ff->pin_Enable(), ce->pin(0));
ff->attribute("LPM_FFType", "DFF");
if (pclk->edge() == NetEvProbe::NEGEDGE)
ff->attribute("Clock:LPM_Polarity", "INVERT");
}
static void make_DFF_CE(Design*des, NetProcTop*top, NetEvWait*wclk, static void make_DFF_CE(Design*des, NetProcTop*top, NetEvWait*wclk,
NetEvent*eclk, NetExpr*cexp, NetAssignBase*asn) NetEvent*eclk, NetExpr*cexp, NetAssignBase*asn)
{ {
@ -150,39 +178,26 @@ static void make_DFF_CE(Design*des, NetProcTop*top, NetEvWait*wclk,
assert(d); assert(d);
// FIXME! NetAssign_*a;
// asn->l_val(0) is good as far as it goes, that's a unsigned rval_pinoffset=0;
// *NetAssign_. Really need to chase the link list to the end, for (unsigned i=0; a=asn->l_val(i); i++) {
// otherwise we don't assign properly to constructs like {a,b}.
// Should turn asn->l_val(0)->lwidth() below into
// asn->lwidth() and follow the linked list of l-values.
NetFF*ff = new NetFF(top->scope(), asn->l_val(0)->name(),
asn->l_val(0)->lwidth());
// asn->l_val(0)->sig() is a *NetNet, which doesn't have the // asn->l_val(i) are the set of *NetAssign_'s that form the list
// loff_ and lwid_ context. Add the correction for loff_ // of lval expressions. Treat each one independently, keeping
// ourselves. // track of which bits of rval to use for each set of DFF inputs.
// For example, given:
// This extra calculations allows for statments like, for // {carry,data} <= x + y + z;
// example: // run through this loop twice, where a and rval_pinoffset are
// lval[7:1] <= foo; // first data and 0, then carry and 1.
// where lval is really a "reg [7:0]". In other words, part // FIXME: ff gets its pin names wrong when loff_ is nonzero.
// selects in the l-value are handled by loff and the lwidth().
int loff = asn->l_val(0)->get_loff();
for (unsigned idx = 0 ; idx < ff->width() ; idx += 1) {
connect(ff->pin_Data(idx), d->bit(idx));
connect(ff->pin_Q(idx), asn->l_val(0)->sig()->pin(idx+loff));
}
connect(ff->pin_Clock(), pclk->pin(0));
if (ce) connect(ff->pin_Enable(), ce->pin(0));
ff->attribute("LPM_FFType", "DFF");
if (pclk->edge() == NetEvProbe::NEGEDGE)
ff->attribute("Clock:LPM_Polarity", "INVERT");
// cerr << "new NetFF named " << a->name() << endl;
NetFF*ff = new NetFF(top->scope(), a->name(),
a->lwidth());
hookup_DFF_CE(ff, d, pclk, ce, a, rval_pinoffset);
des->add_node(ff); des->add_node(ff);
rval_pinoffset += a->lwidth();
}
des->delete_process(top); des->delete_process(top);
} }