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Generate code for MUX devices.

This commit is contained in:
steve 2001-09-01 02:28:42 +00:00
parent 77927972e5
commit 16023cbbd6
3 changed files with 64 additions and 4 deletions
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52
tgt-fpga/d-generic.c
View File

@ -16,7 +16,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ident "$Id: d-generic.c,v 1.5 2001/09/01 02:01:30 steve Exp $"
#ident "$Id: d-generic.c,v 1.6 2001/09/01 02:28:42 steve Exp $"
# include "device.h"
# include "fpga_priv.h"
@ -257,16 +257,64 @@ static void generic_show_cmp_eq(ivl_lpm_t net)
fprintf(xnf, "END\n");
}
/*
* This function draws N-bit wide binary mux devices. These are so
* very popular because they are the result of such expressions as:
*
* x = sel? a : b;
*
* This code only supports the case where sel is a single bit. It
* works by drawing for each bit of the width an EQN device that takes
* as inputs I0 and I1 the alternative inputs, and I2 the select. The
* select bit is common with all the generated mux devices.
*/
static void generic_show_mux(ivl_lpm_t net)
{
char name[1024];
ivl_nexus_t nex, sel;
unsigned idx;
mangle_lpm_name(net, name, sizeof name);
/* Access the single select bit. This is common to the whole
width of the mux. */
assert(ivl_lpm_selects(net) == 1);
sel = ivl_lpm_select(net, 0);
for (idx = 0 ; idx < ivl_lpm_width(net) ; idx += 1) {
fprintf(xnf, "SYM, %s/M%u, EQN, "
"EQN=((I0 * ~I2) + (I1 * I2))\n",
name, idx);
nex = ivl_lpm_q(net, idx);
draw_pin(nex, "O", 'O');
nex = ivl_lpm_data2(net, 0, idx);
draw_pin(nex, "I0", 'I');
nex = ivl_lpm_data2(net, 1, idx);
draw_pin(nex, "I1", 'I');
draw_pin(sel, "I2", 'I');
fprintf(xnf, "END\n");
}
}
const struct device_s d_generic = {
generic_show_logic,
generic_show_dff,
generic_show_cmp_eq,
generic_show_cmp_eq
generic_show_cmp_eq,
generic_show_mux
};
/*
* $Log: d-generic.c,v $
* Revision 1.6 2001/09/01 02:28:42 steve
* Generate code for MUX devices.
*
* Revision 1.5 2001/09/01 02:01:30 steve
* identity compare, and PWR records for constants.
*

7
tgt-fpga/device.h
View File

@ -18,7 +18,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ident "$Id: device.h,v 1.3 2001/09/01 02:01:30 steve Exp $"
#ident "$Id: device.h,v 1.4 2001/09/01 02:28:42 steve Exp $"
# include <ivl_target.h>
@ -43,11 +43,16 @@ struct device_s {
/* These methods show various comparators */
void (*show_cmp_eq)(ivl_lpm_t net);
void (*show_cmp_ne)(ivl_lpm_t net);
/* This method draws MUX devices */
void (*show_mux)(ivl_lpm_t net);
};
/*
* $Log: device.h,v $
* Revision 1.4 2001/09/01 02:28:42 steve
* Generate code for MUX devices.
*
* Revision 1.3 2001/09/01 02:01:30 steve
* identity compare, and PWR records for constants.
*

9
tgt-fpga/gates.c
View File

@ -16,7 +16,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ident "$Id: gates.c,v 1.3 2001/09/01 02:01:30 steve Exp $"
#ident "$Id: gates.c,v 1.4 2001/09/01 02:28:42 steve Exp $"
# include <ivl_target.h>
# include "fpga_priv.h"
@ -62,6 +62,10 @@ static void show_gate_lpm(ivl_lpm_t net)
device->show_dff(net);
break;
case IVL_LPM_MUX:
device->show_mux(net);
break;
default:
fprintf(stderr, "fpga.tgt: unknown LPM type %u\n",
ivl_lpm_type(net));
@ -84,6 +88,9 @@ int show_scope_gates(ivl_scope_t net, void*x)
/*
* $Log: gates.c,v $
* Revision 1.4 2001/09/01 02:28:42 steve
* Generate code for MUX devices.
*
* Revision 1.3 2001/09/01 02:01:30 steve
* identity compare, and PWR records for constants.
*