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/* -*- c -*- */
/*
* Copyright 2007 Free Software Foundation, Inc.
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "mdelay.h"
#include "memory_map.h"
// Delay about one millisecond.
//
// Need 33,333 cycles at 33 MHz.
// Each time around the loop is 10 cycles
//
#define LOOPCNT(wb_div) (MASTER_CLK_RATE/(wb_div) / 10000)
inline static void
delay_1ms(int loop_count)
{
int i;
for (i = 0; i < loop_count; i++){
asm volatile ("or r0, r0, r0\n\
or r0, r0, r0\n\
or r0, r0, r0\n\
or r0, r0, r0\n\
or r0, r0, r0\n\
or r0, r0, r0\n\
or r0, r0, r0\n");
}
}
// delay about ms milliseconds
void
mdelay(int ms)
{
static int loop_count = -1;
if (hwconfig_simulation_p())
return;
if (loop_count < 0){
// set correct loop_count
static unsigned short lc[8] = {
0,
LOOPCNT(1),
LOOPCNT(2),
LOOPCNT(3),
LOOPCNT(4),
LOOPCNT(5),
LOOPCNT(6),
LOOPCNT(7)
};
loop_count = lc[hwconfig_wishbone_divisor() & 0x7];
}
int i;
for (i = 0; i < ms; i++)
delay_1ms(loop_count);
}
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