1 /***************************************************************************
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
10 * Copyright (C) 2002 by Björn Stenberg
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.
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
20 ****************************************************************************/
26 void tick_start(unsigned int interval_in_ms
)
30 count
= CPU_FREQ
* interval_in_ms
/ 1000 / 8;
34 panicf("Error! The tick interval is too long (%d ms)\n",
39 /* We are using timer 0 */
41 TSTR
&= ~0x01; /* Stop the timer */
42 TSNC
&= ~0x01; /* No synchronization */
43 TMDR
&= ~0x01; /* Operate normally */
45 TCNT0
= 0; /* Start counting at 0 */
46 GRA0
= (unsigned short)(count
- 1);
47 TCR0
= 0x23; /* Clear at GRA match, sysclock/8 */
49 /* Enable interrupt on level 1 */
50 IPRC
= (IPRC
& ~0x00f0) | 0x0010;
53 TIER0
= 0xf9; /* Enable GRA match interrupt */
55 TSTR
|= 0x01; /* Start timer 1 */
58 void IMIA0(void) __attribute__ ((interrupt_handler
));
61 /* Run through the list of tick tasks */