timerinit.c

来自「2410 boot loader,usb ftp」· C语言 代码 · 共 37 行

/*
	Copyright 2001-2004 Georges Menie (www.menie.org)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "timer.h"
#include "io.h"


/* initialize the processor's timer register
 */
void timerInit (void)
{
	// 1us = ( PCLK(50MHz) * Divider(1/2) * (Prescaler(24) + 1) * Maximum Interval (1) )

    rTCFG0=(24<<8); // Prescaler for T4
    rTCFG1=(0x0);   // T4 divider 1/2
    rTCNTB4=(0x06);  // T4 Maximum Interval
    rTCON=(1<<22)|(1<<21);  // Manual update, auto reload
    rTCON=(1<<22)|(1<<20);  // Start T4	
	
}