92 lines
1.6 KiB
C

/*
* Copyright © 2008 Keith Packard <keithp@keithp.com>
*
* 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 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
* General Public License for more details.
*
* You should have received a copy of the GNU 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.
*/
sfr at 0x80 P0;
sfr at 0x90 P1;
sfr at 0xA0 P2;
sfr at 0xC6 CLKCON;
sfr at 0xF1 PERCFG;
sfr at 0xF2 ADCCFG;
sfr at 0xF3 P0SEL;
sfr at 0xF4 P1SEL;
sfr at 0xF5 P2SEL;
sfr at 0xFD P0DIR;
sfr at 0xFE P1DIR;
sfr at 0xFF P2DIR;
sfr at 0x8F P0INP;
sfr at 0xF6 P1INP;
sfr at 0xF7 P2INP;
sfr at 0x89 P0IFG;
sfr at 0x8A P1IFG;
sfr at 0x8B P2IFG;
#define nop() _asm nop _endasm;
void
delay (unsigned char n)
{
unsigned char i = 0;
n <<= 1;
while (--n != 0) {
i = 211;
while (--i != 0)
nop();
}
}
void
tone (unsigned char n, unsigned char m)
{
unsigned char i = 0;
while (--m != 0) {
while (--i != 0) {
P2 = 0xff;
delay(n);
P2 = 0xfe;
delay(n);
}
}
}
void
high() {
tone(1, 2);
}
void
low() {
tone(2, 1);
}
main ()
{
CLKCON = 0;
/* Set P2_0 to output */
P2DIR = 0x01;
P1INP = 0x00;
P2INP = 0x00;
for (;;) {
high();
/* low(); */
}
}