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Handle mux sel of X, if inputs are equal.

This commit is contained in:
steve 1999-12-02 04:54:11 +00:00
parent cdb99e7638
commit 88193a369f
2 changed files with 66 additions and 36 deletions
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45
vvm/vvm_gates.cc
View File

@ -23,7 +23,7 @@
* Picture Elements, Inc., 777 Panoramic Way, Berkeley, CA 94704.
*/
#if !defined(WINNT)
#ident "$Id: vvm_gates.cc,v 1.2 1999/11/24 04:38:49 steve Exp $"
#ident "$Id: vvm_gates.cc,v 1.3 1999/12/02 04:54:11 steve Exp $"
#endif
# include "vvm_gates.h"
@ -103,9 +103,52 @@ vpip_bit_t compute_xnor(const vpip_bit_t*inp, unsigned count)
return not(compute_xor(inp,count));
}
void compute_mux(vpip_bit_t*out, unsigned wid,
const vpip_bit_t*sel, unsigned swid,
const vpip_bit_t*dat, unsigned size)
{
unsigned tmp = 0;
for (unsigned idx = 0 ; idx < swid ; idx += 1)
switch (sel[idx]) {
case V0:
break;
case V1:
tmp |= (1<<idx);
break;
default:
tmp = size;
break;
}
if (tmp >= size) {
if (swid > 1) {
for (unsigned idx = 0; idx < wid ; idx += 1)
out[idx] = Vx;
} else {
const unsigned b0 = 0;
const unsigned b1 = wid;
for (unsigned idx = 0 ; idx < wid ; idx += 1) {
if (dat[idx+b0] == dat[idx+b1])
out[idx] = dat[idx+b0];
else
out[idx] = Vx;
}
}
} else {
unsigned b = tmp * wid;
for (unsigned idx = 0; idx < wid ; idx += 1)
out[idx] = dat[idx+b];
}
}
/*
* $Log: vvm_gates.cc,v $
* Revision 1.3 1999/12/02 04:54:11 steve
* Handle mux sel of X, if inputs are equal.
*
* Revision 1.2 1999/11/24 04:38:49 steve
* LT and GT fixes from Eric Aardoom.
*

57
vvm/vvm_gates.h
View File

@ -19,7 +19,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT)
#ident "$Id: vvm_gates.h,v 1.28 1999/11/25 01:34:04 steve Exp $"
#ident "$Id: vvm_gates.h,v 1.29 1999/12/02 04:54:11 steve Exp $"
#endif
# include "vvm.h"
@ -32,6 +32,10 @@ extern vpip_bit_t compute_or(const vpip_bit_t*inp, unsigned count);
extern vpip_bit_t compute_xor(const vpip_bit_t*inp, unsigned count);
extern vpip_bit_t compute_xnor(const vpip_bit_t*inp, unsigned count);
extern void compute_mux(vpip_bit_t*out, unsigned wid,
const vpip_bit_t*sel, unsigned swid,
const vpip_bit_t*dat, unsigned size);
/*
* A vvm gate is constructed with an input width and an output
* function. The input width represents all the input signals that go
@ -403,9 +407,11 @@ template <unsigned WIDTH, unsigned SIZE, unsigned SELWID> class vvm_mux {
public:
explicit vvm_mux()
{ sel_val_ = SIZE;
for (unsigned idx = 0;idx < WIDTH; idx += 1)
out_[idx] = 0;
{ unsigned idx;
for (idx = 0 ; idx < WIDTH ; idx += 1) out_[idx] = 0;
for (idx = 0 ; idx < WIDTH ; idx += 1) output_[idx] = Vx;
for (idx = 0 ; idx < SELWID; idx += 1) sel_[idx] = Vx;
for (idx = 0 ; idx < WIDTH*SIZE; idx += 1) input_[idx] = Vx;
}
void init_Sel(unsigned idx, vpip_bit_t val)
@ -423,11 +429,7 @@ template <unsigned WIDTH, unsigned SIZE, unsigned SELWID> class vvm_mux {
void set_Data(vvm_simulation*sim, unsigned idx, vpip_bit_t val)
{ if (input_[idx] == val) return;
input_[idx] = val;
unsigned sel = idx / WIDTH;
if (sel != sel_val_) return;
unsigned off = idx % WIDTH;
vvm_event*ev = new vvm_out_event(sim, val, out_[off]);
sim->active_event(ev);
evaluate_(sim);
}
void config_rout(unsigned idx, vvm_out_event::action_t o)
@ -436,39 +438,21 @@ template <unsigned WIDTH, unsigned SIZE, unsigned SELWID> class vvm_mux {
private:
vpip_bit_t sel_[SELWID];
vpip_bit_t input_[WIDTH * SIZE];
vpip_bit_t output_[WIDTH];
vvm_out_event::action_t out_[WIDTH];
unsigned sel_val_;
void evaluate_(vvm_simulation*sim)
{ unsigned tmp = 0;
for (unsigned idx = 0 ; idx < SELWID ; idx += 1)
switch (sel_[idx]) {
case V0:
break;
case V1:
tmp |= (1<<idx);
break;
default:
tmp = SIZE;
break;
}
if (tmp > SIZE) tmp = SIZE;
if (tmp == sel_val_) return;
sel_val_ = tmp;
if (sel_val_ == SIZE) {
for (unsigned idx = 0; idx < WIDTH ; idx += 1) {
vvm_event*ev = new vvm_out_event(sim, Vx, out_[idx]);
sim->active_event(ev);
}
} else {
unsigned b = sel_val_ * WIDTH;
for (unsigned idx = 0; idx < WIDTH ; idx += 1) {
{ vpip_bit_t tmp[WIDTH];
compute_mux(tmp, WIDTH, sel_, SELWID, input_, SIZE);
for (unsigned idx = 0 ; idx < WIDTH ; idx += 1)
if (tmp[idx] != output_[idx]) {
output_[idx] = tmp[idx];
vvm_event*ev = new vvm_out_event(sim,
input_[idx+b],
output_[idx],
out_[idx]);
sim->active_event(ev);
}
}
}
};
@ -913,6 +897,9 @@ template <unsigned WIDTH> class vvm_pevent {
/*
* $Log: vvm_gates.h,v $
* Revision 1.29 1999/12/02 04:54:11 steve
* Handle mux sel of X, if inputs are equal.
*
* Revision 1.28 1999/11/25 01:34:04 steve
* Reduce more gate templates to use vvm_1bit_out (Eric Aardoom)
*