Contiki-NG
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cc2420-arch-sfd.c
1/*
2 * Copyright (c) 2009, Swedish Institute of Computer Science
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the Institute nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30
31#include "contiki.h"
32#include "dev/spi-legacy.h"
33#include "cc2420.h"
34#include "isr_compat.h"
35
36extern volatile uint8_t cc2420_sfd_counter;
37extern volatile uint16_t cc2420_sfd_start_time;
38extern volatile uint16_t cc2420_sfd_end_time;
39
40/*---------------------------------------------------------------------------*/
41/* SFD interrupt for timestamping radio packets */
42ISR(TIMERB1, cc2420_timerb1_interrupt)
43{
44 int tbiv;
45
46 /* always read TBIV to clear IFG */
47 tbiv = TBIV;
48 /* read and discard tbiv to avoid "variable set but not used" warning */
49 (void)tbiv;
50 if(CC2420_SFD_IS_1) {
51 cc2420_sfd_counter++;
52 cc2420_sfd_start_time = TBCCR1;
53 } else {
54 cc2420_sfd_counter = 0;
55 cc2420_sfd_end_time = TBCCR1;
56 }
57}
58/*---------------------------------------------------------------------------*/
59void
60cc2420_arch_sfd_init(void)
61{
62 /* Need to select the special function! */
63 CC2420_SFD_PORT(SEL) = BV(CC2420_SFD_PIN);
64
65 /* start timer B - 32768 ticks per second */
66 TBCTL = TBSSEL_1 | TBCLR;
67
68 /* CM_3 = capture mode - capture on both edges */
69 TBCCTL1 = CM_3 | CAP | SCS;
70 TBCCTL1 |= CCIE;
71
72 /* Start Timer_B in continuous mode. */
73 TBCTL |= MC1;
74
75 TBR = RTIMER_NOW();
76}
77/*---------------------------------------------------------------------------*/
CC2420 driver header file.
#define RTIMER_NOW()
Get the current clock time.
Definition rtimer.h:187
Basic SPI macros.