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

Generate blif code for IVL_LPM_SUB device.

This commit is contained in:
Stephen Williams 2013-07-27 19:02:17 -07:00
parent 05f90bcf55
commit 7a6192b5c8
3 changed files with 81 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
tgt-blif/lpm.cc
View File

@ -110,6 +110,9 @@ int print_lpm(FILE*fd, ivl_lpm_t net)
case IVL_LPM_PART_VP:
rc += print_part_vp(fd, net);
break;
case IVL_LPM_SUB:
rc += print_lpm_sub(fd, net);
break;
default:
fprintf(fd, "# XXXX ivl_lpm_type(net) --> %d\n", ivl_lpm_type(net));
fprintf(stderr, "%s:%u: sorry: ivl_lpm_type(net)==%d not implemented.\n",

77
tgt-blif/lpm_add.cc
View File

@ -94,3 +94,80 @@ int print_lpm_add(FILE*fd, ivl_lpm_t net)
return 0;
}
/*
* Cin[0] = 1;
* Cin[n: n!=0] = Cout[n-1]
* assign Q[n] = A[n] ^ (~B[n]) ^ Cin[n];
* assign Cout[n] = A[n]&~B[n] | A[n]&Cin[n] | (~B[n])&Cin[n];
*/
int print_lpm_sub(FILE*fd, ivl_lpm_t net)
{
fprintf(fd, "# %s:%u: IVL_LPM_SUB: width=%u\n",
ivl_lpm_file(net), ivl_lpm_lineno(net), ivl_lpm_width(net));
ivl_nexus_t q_nex = ivl_lpm_q(net);
ivl_nexus_t a_nex = ivl_lpm_data(net,0);
ivl_nexus_t b_nex = ivl_lpm_data(net,1);
blif_nex_data_t*q_ned = blif_nex_data_t::get_nex_data(q_nex);
blif_nex_data_t*a_ned = blif_nex_data_t::get_nex_data(a_nex);
blif_nex_data_t*b_ned = blif_nex_data_t::get_nex_data(b_nex);
assert(ivl_lpm_width(net) == q_ned->get_width());
assert(ivl_lpm_width(net) == a_ned->get_width());
assert(ivl_lpm_width(net) == b_ned->get_width());
// Q[0] = A[0] ^ ~B[0] ^ 1
fprintf(fd, ".names %s%s %s%s %s%s\n"
"01 1\n"
"10 1\n",
a_ned->get_name(), a_ned->get_name_index(0),
b_ned->get_name(), b_ned->get_name_index(0),
q_ned->get_name(), q_ned->get_name_index(0));
if (ivl_lpm_width(net) == 1)
return 0;
// Cout[0] = A[0] & ~B[0] | A[0]&1 | ~B[0]&1
// = A[0] & ~B[0] | A[0] | ~B[0]
// = A[0] | ~B[0]
fprintf(fd, ".names %s%s %s%s %s%s/cout\n"
"1- 1\n"
"-0 1\n",
a_ned->get_name(), a_ned->get_name_index(0),
b_ned->get_name(), b_ned->get_name_index(0),
q_ned->get_name(), q_ned->get_name_index(0));
for (unsigned idx = 1 ; idx < ivl_lpm_width(net) ; idx += 1) {
char cin[128];
snprintf(cin, sizeof cin, "%s%s/cout",
q_ned->get_name(), q_ned->get_name_index(idx-1));
// Q[idx] = A[idx] ^ ~B[idx] ^ cin
fprintf(fd, ".names %s%s %s%s %s %s%s\n"
"011 1\n"
"000 1\n"
"110 1\n"
"101 1\n",
a_ned->get_name(), a_ned->get_name_index(idx),
b_ned->get_name(), b_ned->get_name_index(idx),
cin,
q_ned->get_name(), q_ned->get_name_index(idx));
if ((idx+1) == ivl_lpm_width(net))
continue;
// Cout[idx] = A[idx]&~B[idx] | A[idx]&Cin | ~B[idx]&Cin
fprintf(fd, ".names %s%s %s%s %s %s%s/cout\n"
"001 1\n"
"111 1\n"
"10- 1\n",
a_ned->get_name(), a_ned->get_name_index(idx),
b_ned->get_name(), b_ned->get_name_index(idx),
cin,
q_ned->get_name(), q_ned->get_name_index(idx));
}
return 0;
}

1
tgt-blif/priv.h
View File

@ -32,6 +32,7 @@ extern int print_logic_gate(FILE*fd, ivl_net_logic_t net);
extern int print_lpm(FILE*fd, ivl_lpm_t net);
extern int print_lpm_add(FILE*fd, ivl_lpm_t net);
extern int print_lpm_sub(FILE*fd, ivl_lpm_t net);
/*
* Emit all the constants for a model. This works by scanning the