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add latch primitive for vlog95

This commit is contained in:
Johann Klammer 2016-03-11 21:45:51 +01:00 committed by Martin Whitaker
parent 99afea6946
commit 89333fa3a5
1 changed files with 62 additions and 1 deletions
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63
tgt-vlog95/logic_lpm.c
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@ -364,6 +364,7 @@ static ivl_nexus_t get_lpm_output(ivl_scope_t scope, ivl_lpm_t lpm)
case IVL_LPM_CONCATZ:
case IVL_LPM_DIVIDE:
case IVL_LPM_FF:
case IVL_LPM_LATCH:
case IVL_LPM_MOD:
case IVL_LPM_MULT:
case IVL_LPM_MUX:
@ -1437,8 +1438,27 @@ static void emit_negedge_dff_prim(void)
fprintf(vlog_out, "endprimitive\n");
}
static void emit_latch_prim(void)
{
fprintf(vlog_out, "\n");
fprintf(vlog_out, "/* Icarus generated UDP to represent a synthesized "
"LATCH. */\n");
fprintf(vlog_out, "primitive IVL_LATCH "
"(q, en, d);\n");
fprintf(vlog_out, "%*coutput q;\n", indent_incr, ' ');
fprintf(vlog_out, "%*cinput en, d;\n", indent_incr, ' ');
fprintf(vlog_out, "%*creg q;\n", indent_incr, ' ');
fprintf(vlog_out, "%*ctable\n", indent_incr, ' ');
fprintf(vlog_out, "%*c 1 0 : ? : 0 ;\n", 2*indent_incr, ' ');
fprintf(vlog_out, "%*c 1 1 : ? : 1 ;\n", 2*indent_incr, ' ');
fprintf(vlog_out, "%*c 0 ? : ? : - ;\n", 2*indent_incr, ' ');
fprintf(vlog_out, "%*cendtable\n", indent_incr, ' ');
fprintf(vlog_out, "endprimitive\n");
}
static unsigned need_posedge_dff_prim = 0;
static unsigned need_negedge_dff_prim = 0;
static unsigned need_latch_prim = 0;
/*
* Synthesis creates a D-FF LPM object. To allow this to be simulated as
@ -1456,7 +1476,7 @@ void emit_icarus_generated_udps()
{
/* Emit the copyright information and LGPL note and then emit any
* needed primitives. */
if (need_posedge_dff_prim || need_negedge_dff_prim) {
if (need_posedge_dff_prim || need_negedge_dff_prim || need_latch_prim) {
fprintf(vlog_out,
"\n"
"/*\n"
@ -1484,6 +1504,7 @@ void emit_icarus_generated_udps()
}
if (need_posedge_dff_prim) emit_posedge_dff_prim();
if (need_negedge_dff_prim) emit_negedge_dff_prim();
if (need_latch_prim) emit_latch_prim();
}
static void emit_lpm_ff(ivl_scope_t scope, ivl_lpm_t lpm)
@ -1606,6 +1627,41 @@ static void emit_lpm_ff(ivl_scope_t scope, ivl_lpm_t lpm)
need_posedge_dff_prim = 1;
}
static void emit_lpm_latch(ivl_scope_t scope, ivl_lpm_t lpm)
{
ivl_nexus_t nex;
unsigned emitted;
fprintf(vlog_out, "%*c", indent, ' ');
fprintf(vlog_out, "IVL_LATCH");
emit_lpm_strength(lpm);
/* The lpm LATCH does not support any delays. */
/* The LATCH name is a temporary so we don't bother to print it unless
* we have a range. Then we need to use a made up name. */
if (ivl_lpm_width(lpm) > 1) {
fprintf(vlog_out, " synth_%p [%u:0]", lpm, ivl_lpm_width(lpm)-1U);
}
fprintf(vlog_out, " (");
/* Emit the q pin. */
emit_name_of_nexus(scope, ivl_lpm_q(lpm), 0);
fprintf(vlog_out, ", ");
/* Emit the enable pin expression(s) if needed. */
emitted = 0;
nex = ivl_lpm_enable(lpm);
if (nex) {
emit_nexus_as_ca(scope, nex, 0, 0);
emitted = 1;
}
if (!emitted) fprintf(vlog_out, "1'b1");
fprintf(vlog_out, ", ");
/* Emit the data pin expression(s). */
nex = ivl_lpm_data(lpm, 0);
assert (nex);
emit_nexus_as_ca(scope, nex, 0, 0);
fprintf(vlog_out, ");\n");
need_latch_prim = 1;
}
static ivl_signal_t get_output_from_nexus(ivl_scope_t scope, ivl_nexus_t nex,
int64_t*array_idx)
{
@ -1729,6 +1785,10 @@ void emit_lpm(ivl_scope_t scope, ivl_lpm_t lpm)
emit_lpm_ff(scope, lpm);
return;
}
if (type == IVL_LPM_LATCH) {
emit_lpm_latch(scope, lpm);
return;
}
// HERE: Look for a select passed to a pull device (pr2019553).
/* Skip assignments to a module instantiation input. */
if (output_is_module_instantiation_input(scope, output)) return;
@ -2199,6 +2259,7 @@ void dump_nexus_information(ivl_scope_t scope, ivl_nexus_t nex)
case IVL_LPM_CMP_NEE: fprintf(stderr, "nee"); break;
case IVL_LPM_DIVIDE: fprintf(stderr, "divide"); break;
case IVL_LPM_FF: fprintf(stderr, "dff"); break;
case IVL_LPM_LATCH: fprintf(stderr, "latch"); break;
case IVL_LPM_MOD: fprintf(stderr, "mod"); break;
case IVL_LPM_MULT: fprintf(stderr, "mult"); break;
case IVL_LPM_MUX: fprintf(stderr, "mux"); break;