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- Re-implementation of timing facility using timer0 and the internal clock

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source. Using an external clock source (esp. the real-time clock) did not
  work. This  might as well be a local problem (e.g. hardware).
- Provide some dummy implementations in order to fix the build.
This commit is contained in:
barner 2006-12-22 17:04:38 +00:00
parent 6eb200cfc1
commit 9735acb03f
1 changed files with 99 additions and 21 deletions
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120
cpu/avr/dev/clock.c
View file

@ -5,46 +5,90 @@
#include <avr/io.h>
#include <avr/interrupt.h>
// Hack to see if this sets the blue led...
/* #include "hal_emwinet_demoboard.h" */
static unsigned short count;
static clock_time_t count;
/*---------------------------------------------------------------------------*/
SIGNAL(SIG_OUTPUT_COMPARE0)
{
/* if ((count % 10) > 5) SET_BLUE_LED(); */
/* else CLEAR_BLUE_LED(); */
++count;
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)
{
#if 0
#if __AVR_ENHANCED__
outp(_BV(CS00) | _BV(CS02) | _BV(WGM01), TCCR0);
#else
outp(_BV(CS00) | _BV(CS02) | _BV(CTC0), TCCR0);
#endif
outp(0, TCNT0);
outp((NUT_CPU_FREQ / (128L * CLOCK_CONF_SECOND) + 0.5/*round*/), OCR0);
sbi(TIMSK, OCIE0);
#endif /* 0 */
cli ();
/* Select internal clock */
ASSR = 0x00;
TCCR0 = _BV(CS00) | _BV(CS02) | _BV(WGM01);
/* Set counter to zero */
TCNT0 = 0;
/* OCR0 = AVR_CLK_COUNT;*/
TIMSK |= _BV(OCIE0);
/*
* Set comparison register:
* Crystal freq. is 16000000,
* pre-scale factor is 1024, i.e. we have 125 "ticks" / sec:
* 16000000 = 1024 * 125 * 125
*/
OCR0 = 125;
/*
* Set timer control register:
* - prescale: 1024 (CS00 - CS02)
* - counter reset via comparison register (WGM01)
*/
TCCR0 = _BV(CS00) | _BV(CS01) | _BV(CS02) | _BV(WGM01);
/* Clear interrupt flag register */
TIFR = 0x00;
/*
* Raise interrupt when value in OCR0 is reached. Note that the
* counter value in TCNT0 is cleared automatically.
*/
TIMSK = _BV (OCIE0);
/*
* 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.
*/
count = 0;
sei ();
}
/*---------------------------------------------------------------------------*/
clock_time_t
clock_time(void)
@ -52,3 +96,37 @@ clock_time(void)
return count;
}
/*---------------------------------------------------------------------------*/
/**
* Delay the CPU for a multiple of TODO
*/
void
clock_delay(unsigned int i)
{
// TODO
}
/*---------------------------------------------------------------------------*/
/**
* 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)
{
return count / CLOCK_SECOND;
}