nes-proj/cpu/avr/dev/clock.c

125 lines
2.3 KiB
C

#include "sys/clock.h"
#include "dev/clock-avr.h"
#include "sys/etimer.h"
#include <avr/io.h>
#include <avr/interrupt.h>
static volatile clock_time_t count, scount;
static volatile unsigned long seconds;
/*---------------------------------------------------------------------------*/
//SIGNAL(SIG_OUTPUT_COMPARE0)
ISR(AVR_OUTPUT_COMPARE_INT)
{
count++;
if(++scount == CLOCK_SECOND) {
scount = 0;
seconds++;
}
if(etimer_pending()) {
etimer_request_poll();
}
}
/* External clock source does not work ? */
#if 0
void
clock_init(void)
{
cli ();
TIMSK &= ((unsigned char)~(1 << (TOIE0)));
TIMSK &= ((unsigned char)~(1 << (OCIE0)));
/* Disable TC0 interrupt */
/**
* set Timer/Counter0 to be asynchronous
* from the CPU clock with a second external
* clock(32,768kHz)driving it
*/
ASSR |= (1 << (AS0));
TCCR0 = _BV (CS02) | _BV (CS01) | _BV (WGM1);
TCNT0 = 0;
OCR0 = 128;
TIMSK |= (1 << (OCIE0));
TIMSK |= (1 << (TOIE0));
sei ();
}
#endif
/*---------------------------------------------------------------------------*/
void
clock_init(void)
{
cli ();
OCRSetup();
/*
* Counts the number of ticks. Since clock_time_t is an unsigned
* 16 bit data type, time intervals of up to 524 seconds can be
* measured.
*/
scount = count = 0;
sei ();
}
/*---------------------------------------------------------------------------*/
clock_time_t
clock_time(void)
{
clock_time_t tmp;
do {
tmp = count;
} while(tmp != count);
return tmp;
}
/*---------------------------------------------------------------------------*/
/**
* Delay the CPU for a multiple of TODO
*/
void
clock_delay(unsigned int i)
{
for (; i > 0; i--) { /* Needs fixing XXX */
unsigned j;
for (j = 50; j > 0; j--)
asm volatile("nop");
}
}
/*---------------------------------------------------------------------------*/
/**
* Wait for a multiple of 1 / 125 sec = 0.008 ms.
*
*/
void
clock_wait(int i)
{
clock_time_t start;
start = clock_time();
while(clock_time() - start < (clock_time_t)i);
}
/*---------------------------------------------------------------------------*/
void
clock_set_seconds(unsigned long sec)
{
// TODO
}
unsigned long
clock_seconds(void)
{
unsigned long tmp;
do {
tmp = seconds;
} while(tmp != seconds);
return tmp;
}