usleep.c

这是TFTP 协议的最新源代码 很辛苦的

/*
	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 "68vz328.h"
#include "io.h"

/* waiting loop controled by the 1us timer
 */
void usleep (int t)
{
	unsigned short start, stop;

	start = readw (TCN1);
	while (t > 0 && (readw (TCTL1) & 1)) {
		stop = readw (TCN1);
		t -= (unsigned short) (stop - start);
		start = stop;
	}
}