luke
/
iverilog
mirror of https://github.com/steveicarus/iverilog.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix some bit based delays in continuous assignments. 

This patch fixes some of the delays in bit based continuous
assignments (unary -, unary +constants, string constants,
reduction operators and user functions).

Use draw_lpm_output_delay() in all functions that need it.
This commit is contained in:
Cary R 2008-01-29 09:46:14 -08:00 committed by Stephen Williams
parent d9ac146b8f
commit 1609de6ed9
2 changed files with 110 additions and 88 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

157
elab_net.cc
View File

@ -2731,16 +2731,17 @@ NetNet* PENumber::elaborate_net(Design*des, NetScope*scope,
Link::strength_t drive0,
Link::strength_t drive1) const
{
NetNet *net;
NetConst *con;
/* If we are constrained by a l-value size, then just make a
number constant with the correct size and set as many bits
in that constant as make sense. Pad excess with
zeros. Also, assume that numbers are meant to be logic
type. */
if (lwidth > 0) {
NetNet*net = new NetNet(scope, scope->local_symbol(),
NetNet::IMPLICIT, lwidth);
net = new NetNet(scope, scope->local_symbol(),
NetNet::IMPLICIT, lwidth);
net->data_type(IVL_VT_LOGIC);
net->local_flag(true);
net->set_signed(value_->has_sign());
@ -2749,72 +2750,90 @@ NetNet* PENumber::elaborate_net(Design*des, NetScope*scope,
if (num.len() > lwidth)
num = verinum(num, lwidth);
NetConst*tmp = new NetConst(scope, scope->local_symbol(), num);
tmp->pin(0).drive0(drive0);
tmp->pin(0).drive1(drive1);
connect(net->pin(0), tmp->pin(0));
des->add_node(tmp);
return net;
}
con = new NetConst(scope, scope->local_symbol(), num);
con->pin(0).drive0(drive0);
con->pin(0).drive1(drive1);
/* If the number has a length, then use that to size the
number. Generate a constant object of exactly the user
specified size. */
if (value_->has_len()) {
NetNet*net = new NetNet(scope, scope->local_symbol(),
NetNet::IMPLICIT, value_->len());
} else if (value_->has_len()) {
net = new NetNet(scope, scope->local_symbol(),
NetNet::IMPLICIT, value_->len());
net->data_type(IVL_VT_LOGIC);
net->local_flag(true);
net->set_signed(value_->has_sign());
NetConst*tmp = new NetConst(scope, scope->local_symbol(),
*value_);
connect(net->pin(0), tmp->pin(0));
des->add_node(tmp);
return net;
}
con = new NetConst(scope, scope->local_symbol(),
*value_);
/* None of the above tight constraints are present, so make a
plausible choice for the width. Try to reduce the width as
much as possible by eliminating high zeros of unsigned
numbers. */
} else {
if (must_be_self_determined_flag) {
cerr << get_fileline() << ": error: No idea how wide to make "
<< "the unsized constant " << *value_ << "." << endl;
des->errors += 1;
}
unsigned width = value_->len();
if (value_->has_sign() && (value_->get(width-1) == verinum::V0)) {
/* If the number is signed, but known to be positive,
then reduce it down as if it were unsigned. */
while (width > 1) {
if (value_->get(width-1) != verinum::V0)
break;
width -= 1;
if (must_be_self_determined_flag) {
cerr << get_fileline() << ": error: No idea how wide to "
<< "make the unsized constant " << *value_ << "." << endl;
des->errors += 1;
}
} else if (value_->has_sign() == false) {
while ( (width > 1) && (value_->get(width-1) == verinum::V0))
width -= 1;
unsigned width = value_->len();
if (value_->has_sign() && (value_->get(width-1) == verinum::V0)) {
/* If the number is signed, but known to be positive,
then reduce it down as if it were unsigned. */
while (width > 1) {
if (value_->get(width-1) != verinum::V0)
break;
width -= 1;
}
} else if (value_->has_sign() == false) {
while ( (width > 1) && (value_->get(width-1) == verinum::V0))
width -= 1;
}
verinum num (verinum::V0, width);
for (unsigned idx = 0 ; idx < width ; idx += 1)
num.set(idx, value_->get(idx));
net = new NetNet(scope, scope->local_symbol(),
NetNet::IMPLICIT, width);
net->data_type(IVL_VT_LOGIC);
net->local_flag(true);
con = new NetConst(scope, scope->local_symbol(), num);
}
verinum num (verinum::V0, width);
for (unsigned idx = 0 ; idx < width ; idx += 1)
num.set(idx, value_->get(idx));
/* If there are non-zero output delays, then create bufz
devices to carry the propagation delays. Otherwise, just
connect the result to the output. */
if (rise || fall || decay) {
NetNet*tmp = new NetNet(scope, scope->local_symbol(),
NetNet::WIRE, net->vector_width());
tmp->data_type(IVL_VT_LOGIC);
tmp->local_flag(true);
NetNet*net = new NetNet(scope, scope->local_symbol(),
NetNet::IMPLICIT, width);
net->data_type(IVL_VT_LOGIC);
net->local_flag(true);
NetConst*tmp = new NetConst(scope, scope->local_symbol(), num);
connect(net->pin(0), tmp->pin(0));
NetBUFZ*tmpz = new NetBUFZ(scope, scope->local_symbol(),
net->vector_width());
tmpz->rise_time(rise);
tmpz->fall_time(fall);
tmpz->decay_time(decay);
tmpz->pin(0).drive0(drive0);
tmpz->pin(0).drive1(drive1);
des->add_node(tmp);
connect(con->pin(0), tmp->pin(0));
connect(tmp->pin(0), tmpz->pin(1));
connect(net->pin(0), tmpz->pin(0));
des->add_node(tmpz);
} else {
connect(con->pin(0), net->pin(0));
}
des->add_node(con);
return net;
}
@ -2858,11 +2877,35 @@ NetNet* PEString::elaborate_net(Design*des, NetScope*scope,
num.set(idx, (byte & mask)? verinum::V1 : verinum::V0);
}
NetConst*tmp = new NetConst(scope, scope->local_symbol(), num);
tmp->set_line(*this);
des->add_node(tmp);
NetConst*con = new NetConst(scope, scope->local_symbol(), num);
con->set_line(*this);
des->add_node(con);
connect(net->pin(0), tmp->pin(0));
/* If there are non-zero output delays, then create bufz
devices to carry the propagation delays. Otherwise, just
connect the result to the output. */
if (rise || fall || decay) {
NetNet*tmp = new NetNet(scope, scope->local_symbol(),
NetNet::WIRE, net->vector_width());
tmp->data_type(IVL_VT_LOGIC);
tmp->local_flag(true);
NetBUFZ*tmpz = new NetBUFZ(scope, scope->local_symbol(),
net->vector_width());
tmpz->rise_time(rise);
tmpz->fall_time(fall);
tmpz->decay_time(decay);
tmpz->pin(0).drive0(drive0);
tmpz->pin(0).drive1(drive1);
connect(con->pin(0), tmp->pin(0));
connect(tmp->pin(0), tmpz->pin(1));
connect(net->pin(0), tmpz->pin(0));
des->add_node(tmpz);
} else {
connect(con->pin(0), net->pin(0));
}
return net;
}
@ -3161,6 +3204,7 @@ NetNet* PEUnary::elaborate_net(Design*des, NetScope*scope,
connect(gate->pin(0), sig->pin(0));
connect(gate->pin(1), sub_sig->pin(0));
des->add_node(gate);
gate->set_line(*this);
gate->rise_time(rise);
gate->fall_time(fall);
gate->decay_time(decay);
@ -3171,7 +3215,10 @@ NetNet* PEUnary::elaborate_net(Design*des, NetScope*scope,
sig->vector_width());
sub->attribute(perm_string::literal("LPM_Direction"),
verinum("SUB"));
sub->set_line(*this);
sub->rise_time(rise);
sub->fall_time(fall);
sub->decay_time(decay);
des->add_node(sub);
connect(sig->pin(0), sub->pin_Result());

41
tgt-vvp/vvp_scope.c
View File

@ -1793,21 +1793,7 @@ static void draw_lpm_cmp(ivl_lpm_t net)
draw_lpm_data_inputs(net, 0, 2, src_table);
ivl_expr_t d_rise = ivl_lpm_delay(net, 0);
ivl_expr_t d_fall = ivl_lpm_delay(net, 1);
ivl_expr_t d_decay = ivl_lpm_delay(net, 2);
const char*dly = "";
if (d_rise != 0) {
assert(number_is_immediate(d_rise, 64));
assert(number_is_immediate(d_fall, 64));
assert(number_is_immediate(d_decay, 64));
dly = "/d";
fprintf(vvp_out, "L_%p .delay (%lu,%lu,%lu) L_%p/d;\n",
net, get_number_immediate(d_rise),
get_number_immediate(d_rise),
get_number_immediate(d_rise), net);
}
const char*dly = draw_lpm_output_delay(net);
fprintf(vvp_out, "L_%p%s .cmp/%s%s %u, %s, %s;\n",
net, dly, type, signed_string, width,
@ -2065,23 +2051,10 @@ static void draw_type_string_of_nex(ivl_nexus_t nex)
static void draw_lpm_sfunc(ivl_lpm_t net)
{
ivl_expr_t d_rise = ivl_lpm_delay(net, 0);
ivl_expr_t d_fall = ivl_lpm_delay(net, 1);
ivl_expr_t d_decay = ivl_lpm_delay(net, 2);
const char*dly = "";
if (d_rise != 0) {
assert(number_is_immediate(d_rise, 64));
assert(number_is_immediate(d_fall, 64));
assert(number_is_immediate(d_decay, 64));
dly = "/d";
fprintf(vvp_out, "L_%p .delay (%lu,%lu,%lu) L_%p/d;\n",
net, get_number_immediate(d_rise),
get_number_immediate(d_rise),
get_number_immediate(d_rise), net);
}
unsigned idx;
const char*dly = draw_lpm_output_delay(net);
fprintf(vvp_out, "L_%p%s .sfunc %u %u \"%s\"", net, dly,
ivl_file_table_index(ivl_lpm_file(net)), ivl_lpm_lineno(net),
ivl_lpm_string(net));
@ -2285,8 +2258,10 @@ static void draw_lpm_part_bi(ivl_lpm_t net)
*/
static void draw_lpm_re(ivl_lpm_t net, const char*type)
{
fprintf(vvp_out, "L_%p .reduce/%s %s;\n",
net, type, draw_net_input(ivl_lpm_data(net,0)));
const char*dly = draw_lpm_output_delay(net);
fprintf(vvp_out, "L_%p%s .reduce/%s %s;\n", net, dly,
type, draw_net_input(ivl_lpm_data(net,0)));
}
static void draw_lpm_repeat(ivl_lpm_t net)