nes-proj/arch/cpu/msp430/cc2420-arch-sfd.c
2017-10-12 23:57:38 +02:00

78 lines
2.8 KiB
C

/*
* Copyright (c) 2009, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include "contiki.h"
#include "dev/spi.h"
#include "cc2420.h"
#include "isr_compat.h"
extern volatile uint8_t cc2420_sfd_counter;
extern volatile uint16_t cc2420_sfd_start_time;
extern volatile uint16_t cc2420_sfd_end_time;
/*---------------------------------------------------------------------------*/
/* SFD interrupt for timestamping radio packets */
ISR(TIMERB1, cc2420_timerb1_interrupt)
{
int tbiv;
/* always read TBIV to clear IFG */
tbiv = TBIV;
/* read and discard tbiv to avoid "variable set but not used" warning */
(void)tbiv;
if(CC2420_SFD_IS_1) {
cc2420_sfd_counter++;
cc2420_sfd_start_time = TBCCR1;
} else {
cc2420_sfd_counter = 0;
cc2420_sfd_end_time = TBCCR1;
}
}
/*---------------------------------------------------------------------------*/
void
cc2420_arch_sfd_init(void)
{
/* Need to select the special function! */
CC2420_SFD_PORT(SEL) = BV(CC2420_SFD_PIN);
/* start timer B - 32768 ticks per second */
TBCTL = TBSSEL_1 | TBCLR;
/* CM_3 = capture mode - capture on both edges */
TBCCTL1 = CM_3 | CAP | SCS;
TBCCTL1 |= CCIE;
/* Start Timer_B in continuous mode. */
TBCTL |= MC1;
TBR = RTIMER_NOW();
}
/*---------------------------------------------------------------------------*/