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authorDavid A. Mellis <d.mellis@arduino.cc>2009-11-07 17:05:21 +0000
committerDavid A. Mellis <d.mellis@arduino.cc>2009-11-07 17:05:21 +0000
commit584dece7b0c982de8731f7400c94b5034aef89e7 (patch)
treef2d254ac1200e0517fc707d281c48669bec06f59 /cores/arduino/wiring.c
parent7d31607442b61b57e9cc794e7f15d6322553e3f0 (diff)
Moving things around.
Diffstat (limited to 'cores/arduino/wiring.c')
-rwxr-xr-xcores/arduino/wiring.c250
1 files changed, 0 insertions, 250 deletions
diff --git a/cores/arduino/wiring.c b/cores/arduino/wiring.c
deleted file mode 100755
index 72bc282..0000000
--- a/cores/arduino/wiring.c
+++ /dev/null
@@ -1,250 +0,0 @@
-/*
- wiring.c - Partial implementation of the Wiring API for the ATmega8.
- Part of Arduino - http://www.arduino.cc/
-
- Copyright (c) 2005-2006 David A. Mellis
-
- This library 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 2.1 of the License, or (at your option) any later version.
-
- This library 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 library; if not, write to the
- Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- Boston, MA 02111-1307 USA
-
- $Id$
-*/
-
-#include "wiring_private.h"
-
-// the prescaler is set so that timer0 ticks every 64 clock cycles, and the
-// the overflow handler is called every 256 ticks.
-#define MICROSECONDS_PER_TIMER0_OVERFLOW (clockCyclesToMicroseconds(64 * 256))
-
-// the whole number of milliseconds per timer0 overflow
-#define MILLIS_INC (MICROSECONDS_PER_TIMER0_OVERFLOW / 1000)
-
-// the fractional number of milliseconds per timer0 overflow. we shift right
-// by three to fit these numbers into a byte. (for the clock speeds we care
-// about - 8 and 16 MHz - this doesn't lose precision.)
-#define FRACT_INC ((MICROSECONDS_PER_TIMER0_OVERFLOW % 1000) >> 3)
-#define FRACT_MAX (1000 >> 3)
-
-volatile unsigned long timer0_overflow_count = 0;
-volatile unsigned long timer0_millis = 0;
-static unsigned char timer0_fract = 0;
-
-SIGNAL(TIMER0_OVF_vect)
-{
- // copy these to local variables so they can be stored in registers
- // (volatile variables must be read from memory on every access)
- unsigned long m = timer0_millis;
- unsigned char f = timer0_fract;
-
- m += MILLIS_INC;
- f += FRACT_INC;
- if (f >= FRACT_MAX) {
- f -= FRACT_MAX;
- m += 1;
- }
-
- timer0_fract = f;
- timer0_millis = m;
- timer0_overflow_count++;
-}
-
-unsigned long millis()
-{
- unsigned long m;
- uint8_t oldSREG = SREG;
-
- // disable interrupts while we read timer0_millis or we might get an
- // inconsistent value (e.g. in the middle of a write to timer0_millis)
- cli();
- m = timer0_millis;
- SREG = oldSREG;
-
- return m;
-}
-
-unsigned long micros() {
- unsigned long m, t;
- uint8_t oldSREG = SREG;
-
- cli();
- t = TCNT0;
-
-#ifdef TIFR0
- if ((TIFR0 & _BV(TOV0)) && (t == 0))
- t = 256;
-#else
- if ((TIFR & _BV(TOV0)) && (t == 0))
- t = 256;
-#endif
-
- m = timer0_overflow_count;
- SREG = oldSREG;
-
- return ((m << 8) + t) * (64 / clockCyclesPerMicrosecond());
-}
-
-void delay(unsigned long ms)
-{
- unsigned long start = millis();
-
- while (millis() - start <= ms)
- ;
-}
-
-/* Delay for the given number of microseconds. Assumes a 8 or 16 MHz clock.
- * Disables interrupts, which will disrupt the millis() function if used
- * too frequently. */
-void delayMicroseconds(unsigned int us)
-{
- uint8_t oldSREG;
-
- // calling avrlib's delay_us() function with low values (e.g. 1 or
- // 2 microseconds) gives delays longer than desired.
- //delay_us(us);
-
-#if F_CPU >= 16000000L
- // for the 16 MHz clock on most Arduino boards
-
- // for a one-microsecond delay, simply return. the overhead
- // of the function call yields a delay of approximately 1 1/8 us.
- if (--us == 0)
- return;
-
- // the following loop takes a quarter of a microsecond (4 cycles)
- // per iteration, so execute it four times for each microsecond of
- // delay requested.
- us <<= 2;
-
- // account for the time taken in the preceeding commands.
- us -= 2;
-#else
- // for the 8 MHz internal clock on the ATmega168
-
- // for a one- or two-microsecond delay, simply return. the overhead of
- // the function calls takes more than two microseconds. can't just
- // subtract two, since us is unsigned; we'd overflow.
- if (--us == 0)
- return;
- if (--us == 0)
- return;
-
- // the following loop takes half of a microsecond (4 cycles)
- // per iteration, so execute it twice for each microsecond of
- // delay requested.
- us <<= 1;
-
- // partially compensate for the time taken by the preceeding commands.
- // we can't subtract any more than this or we'd overflow w/ small delays.
- us--;
-#endif
-
- // disable interrupts, otherwise the timer 0 overflow interrupt that
- // tracks milliseconds will make us delay longer than we want.
- oldSREG = SREG;
- cli();
-
- // busy wait
- __asm__ __volatile__ (
- "1: sbiw %0,1" "\n\t" // 2 cycles
- "brne 1b" : "=w" (us) : "0" (us) // 2 cycles
- );
-
- // reenable interrupts.
- SREG = oldSREG;
-}
-
-void init()
-{
- // this needs to be called before setup() or some functions won't
- // work there
- sei();
-
- // on the ATmega168, timer 0 is also used for fast hardware pwm
- // (using phase-correct PWM would mean that timer 0 overflowed half as often
- // resulting in different millis() behavior on the ATmega8 and ATmega168)
-#if !defined(__AVR_ATmega8__)
- sbi(TCCR0A, WGM01);
- sbi(TCCR0A, WGM00);
-#endif
- // set timer 0 prescale factor to 64
-#if defined(__AVR_ATmega8__)
- sbi(TCCR0, CS01);
- sbi(TCCR0, CS00);
-#else
- sbi(TCCR0B, CS01);
- sbi(TCCR0B, CS00);
-#endif
- // enable timer 0 overflow interrupt
-#if defined(__AVR_ATmega8__)
- sbi(TIMSK, TOIE0);
-#else
- sbi(TIMSK0, TOIE0);
-#endif
-
- // timers 1 and 2 are used for phase-correct hardware pwm
- // this is better for motors as it ensures an even waveform
- // note, however, that fast pwm mode can achieve a frequency of up
- // 8 MHz (with a 16 MHz clock) at 50% duty cycle
-
- // set timer 1 prescale factor to 64
- sbi(TCCR1B, CS11);
- sbi(TCCR1B, CS10);
- // put timer 1 in 8-bit phase correct pwm mode
- sbi(TCCR1A, WGM10);
-
- // set timer 2 prescale factor to 64
-#if defined(__AVR_ATmega8__)
- sbi(TCCR2, CS22);
-#else
- sbi(TCCR2B, CS22);
-#endif
- // configure timer 2 for phase correct pwm (8-bit)
-#if defined(__AVR_ATmega8__)
- sbi(TCCR2, WGM20);
-#else
- sbi(TCCR2A, WGM20);
-#endif
-
-#if defined(__AVR_ATmega1280__)
- // set timer 3, 4, 5 prescale factor to 64
- sbi(TCCR3B, CS31); sbi(TCCR3B, CS30);
- sbi(TCCR4B, CS41); sbi(TCCR4B, CS40);
- sbi(TCCR5B, CS51); sbi(TCCR5B, CS50);
- // put timer 3, 4, 5 in 8-bit phase correct pwm mode
- sbi(TCCR3A, WGM30);
- sbi(TCCR4A, WGM40);
- sbi(TCCR5A, WGM50);
-#endif
-
- // set a2d prescale factor to 128
- // 16 MHz / 128 = 125 KHz, inside the desired 50-200 KHz range.
- // XXX: this will not work properly for other clock speeds, and
- // this code should use F_CPU to determine the prescale factor.
- sbi(ADCSRA, ADPS2);
- sbi(ADCSRA, ADPS1);
- sbi(ADCSRA, ADPS0);
-
- // enable a2d conversions
- sbi(ADCSRA, ADEN);
-
- // the bootloader connects pins 0 and 1 to the USART; disconnect them
- // here so they can be used as normal digital i/o; they will be
- // reconnected in Serial.begin()
-#if defined(__AVR_ATmega8__)
- UCSRB = 0;
-#else
- UCSR0B = 0;
-#endif
-} \ No newline at end of file