mspdebug/simio/simio_hwmult.c

166 lines
3.5 KiB
C

/* MSPDebug - debugging tool for MSP430 MCUs
* Copyright (C) 2009, 2010 Daniel Beer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <string.h>
#include "simio_device.h"
#include "simio_hwmult.h"
#include "output.h"
#include "expr.h"
/* Multiplier register addresses - taken from mspgcc */
#define MPY 0x0130 /* Multiply Unsigned/Operand 1 */
#define MPYS 0x0132 /* Multiply Signed/Operand 1 */
#define MAC 0x0134 /* Multiply Unsigned and Accumulate/Operand 1 */
#define MACS 0x0136 /* Multiply Signed and Accumulate/Operand 1 */
#define OP2 0x0138 /* Operand 2 */
#define RESLO 0x013A /* Result Low Word */
#define RESHI 0x013C /* Result High Word */
#define SUMEXT 0x013E /* Sum Extend */
struct hwmult {
struct simio_device base;
int mode;
uint16_t op1;
uint16_t op2;
uint32_t result;
uint16_t sumext;
};
struct simio_device *hwmult_create(char **arg_text)
{
struct hwmult *h = malloc(sizeof(*h));
(void)arg_text;
if (!h) {
pr_error("hwmult: can't allocate memory");
return NULL;
}
memset(h, 0, sizeof(*h));
h->base.type = &simio_hwmult;
return (struct simio_device *)h;
}
static void hwmult_destroy(struct simio_device *dev)
{
free(dev);
}
static void do_multiply(struct hwmult *h)
{
uint32_t im;
/* Multiply */
if (h->mode & 2)
im = (int16_t)h->op1 * (int16_t)h->op2;
else
im = h->op1 * h->op2;
/* Accumulate or store */
if (h->mode & 4)
h->result += im;
else
h->result = im;
/* Set SUMEXT */
if (h->mode & 2)
h->sumext = (h->result & 0x80000000) ? 0xffff : 0;
else if (h->mode == MPY)
h->sumext = (h->result < im) ? 1 : 0;
else
h->sumext = 0;
}
static int hwmult_write(struct simio_device *dev, address_t addr, uint16_t data)
{
struct hwmult *h = (struct hwmult *)dev;
switch (addr) {
case RESHI:
h->result = (h->result & 0xffff) | ((uint32_t)data << 16);
return 0;
case RESLO:
h->result = (h->result & 0xffff0000) | data;
return 0;
case OP2:
h->op2 = data;
do_multiply(h);
return 0;
case MPY:
case MPYS:
case MAC:
case MACS:
h->op1 = data;
h->mode = addr;
return 0;
}
return 1;
}
static int hwmult_read(struct simio_device *dev, address_t addr, uint16_t *data)
{
struct hwmult *h = (struct hwmult *)dev;
switch (addr) {
case MPY:
case MPYS:
case MAC:
case MACS:
*data = h->op1;
return 0;
case OP2:
*data = h->op2;
return 0;
case RESLO:
*data = h->result & 0xffff;
return 0;
case RESHI:
*data = h->result >> 16;
return 0;
case SUMEXT:
*data = h->sumext;
return 0;
}
return 1;
}
const struct simio_class simio_hwmult = {
.name = "hwmult",
.help =
"This module simulates the hardware multiplier.\n",
.create = hwmult_create,
.destroy = hwmult_destroy,
.write = hwmult_write,
.read = hwmult_read
};