| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2002 by Björn Stenberg |
| * |
| * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY |
| * KIND, either express or implied. |
| * |
| ****************************************************************************/ |
| #include "config.h" |
| #include "system.h" |
| #include "kernel.h" |
| #include "panic.h" |
| |
| void tick_start(unsigned int interval_in_ms) |
| { |
| unsigned long count; |
| int prescale; |
| |
| count = CPU_FREQ/2 * interval_in_ms / 1000 / 16; |
| |
| if(count > 0x10000) |
| { |
| panicf("Error! The tick interval is too long (%d ms)\n", |
| interval_in_ms); |
| return; |
| } |
| |
| prescale = cpu_frequency / CPU_FREQ; |
| /* Note: The prescaler is later adjusted on-the-fly on CPU frequency |
| changes within timer.c */ |
| |
| /* We are using timer 0 */ |
| |
| TRR0 = (unsigned short)(count - 1); /* The reference count */ |
| TCN0 = 0; /* reset the timer */ |
| TMR0 = 0x001d | ((unsigned short)(prescale - 1) << 8); |
| /* restart, CLK/16, enabled, prescaler */ |
| |
| TER0 = 0xff; /* Clear all events */ |
| |
| ICR1 = 0x8c; /* Interrupt on level 3.0 */ |
| coldfire_imr_mod(0x000, 0x200); |
| } |
| |
| void TIMER0(void) __attribute__ ((interrupt_handler)); |
| void TIMER0(void) |
| { |
| /* Run through the list of tick tasks */ |
| call_tick_tasks(); |
| |
| TER0 = 0xff; /* Clear all events */ |
| } |