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-rw-r--r--firmware/target/sh/kernel-sh.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/firmware/target/sh/kernel-sh.c b/firmware/target/sh/kernel-sh.c
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1/***************************************************************************
2 * __________ __ ___.
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
7 * \/ \/ \/ \/ \/
8 * $Id$
9 *
10 * Copyright (C) 2002 by Björn Stenberg
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
16 *
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
19 *
20 ****************************************************************************/
21#include "config.h"
22#include "system.h"
23#include "kernel.h"
24#include "panic.h"
25
26void tick_start(unsigned int interval_in_ms)
27{
28 unsigned long count;
29
30 count = CPU_FREQ * interval_in_ms / 1000 / 8;
31
32 if(count > 0x10000)
33 {
34 panicf("Error! The tick interval is too long (%d ms)\n",
35 interval_in_ms);
36 return;
37 }
38
39 /* We are using timer 0 */
40
41 TSTR &= ~0x01; /* Stop the timer */
42 TSNC &= ~0x01; /* No synchronization */
43 TMDR &= ~0x01; /* Operate normally */
44
45 TCNT0 = 0; /* Start counting at 0 */
46 GRA0 = (unsigned short)(count - 1);
47 TCR0 = 0x23; /* Clear at GRA match, sysclock/8 */
48
49 /* Enable interrupt on level 1 */
50 IPRC = (IPRC & ~0x00f0) | 0x0010;
51
52 TSR0 &= ~0x01;
53 TIER0 = 0xf9; /* Enable GRA match interrupt */
54
55 TSTR |= 0x01; /* Start timer 1 */
56}
57
58void IMIA0(void) __attribute__ ((interrupt_handler));
59void IMIA0(void)
60{
61 /* Run through the list of tick tasks */
62 call_tick_tasks();
63
64 TSR0 &= ~0x01;
65}