--- /dev/null
+/*
+ * Copyright (c) 2008, Technische Universitaet Berlin
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * extraification, are permitted provided that the following conditions
+ * are met:
+ * - Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * - 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.
+ * - Neither the name of the Technische Universitaet Berlin 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 COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ *
+ * - Revision -------------------------------------------------------------
+ * $Revision$
+ * $Date$
+ * @author: Jan Hauer <hauer@tkn.tu-berlin.de>
+ * ========================================================================
+ */
+
+/**
+ * In slotted CSMA-CA frames must be sent on backoff boundaries (slot width:
+ * 320 us). The MicaZ platform lacks a clock with sufficient precision and
+ * accuracy, i.e. for slotted CSMA-CA the timing is *not* standard compliant
+ * (this code is experimental)
+ */
+
+#include "TKN154_platform.h"
+module TKN154TimingP
+{
+ provides interface CaptureTime;
+ provides interface ReliableWait;
+ provides interface ReferenceTime;
+ uses interface TimeCalc;
+ uses interface GetNow<bool> as CCA;
+ uses interface Alarm<T62500hz,uint32_t> as SymbolAlarm;
+ uses interface Leds;
+}
+implementation
+{
+ enum {
+ S_WAIT_OFF,
+ S_WAIT_RX,
+ S_WAIT_TX,
+ S_WAIT_BACKOFF,
+ };
+ uint8_t m_state = S_WAIT_OFF;
+
+ async command error_t CaptureTime.convert(uint16_t time, ieee154_timestamp_t *localTime, int16_t offset)
+ {
+ // Timer1 is used for capturing, it is sourced by ACLK (32768Hz),
+ // we now need to convert the capture "time" into ieee154_timestamp_t.
+ // With the 32768Hz quartz we don't have enough precision anyway,
+ // so the code below generates a timestamp that is not accurate
+
+ uint16_t tcnt1, delta;
+ uint32_t now;
+ atomic {
+ tcnt1 = TCNT1;
+ now = call SymbolAlarm.getNow();
+ }
+ if (time < tcnt1)
+ delta = tcnt1 - time;
+ else
+ delta = ~(time - tcnt1) + 1;
+ *localTime = now - delta * 2 + offset; // one tick of Timer1 ~ two symbols
+
+ return SUCCESS;
+ }
+
+ async command bool ReliableWait.ccaOnBackoffBoundary(ieee154_timestamp_t *slot0)
+ {
+ // There is no point in trying
+ return (call CCA.getNow() ? 20: 0);
+ }
+
+ async command bool CaptureTime.isValidTimestamp(uint16_t risingSFDTime, uint16_t fallingSFDTime)
+ {
+ // smallest packet (ACK) takes
+ // length field (1) + MPDU (5) = 6 byte => 12 * 16 us = 192 us
+ return (fallingSFDTime - risingSFDTime) > 5;
+ }
+
+ async command void ReliableWait.waitRx(uint32_t t0, uint32_t dt)
+ {
+ if (m_state != S_WAIT_OFF){
+ ASSERT(0);
+ return;
+ }
+ m_state = S_WAIT_RX;
+ call SymbolAlarm.startAt(t0 - 16, dt); // subtract 12 symbols required for Rx calibration
+ }
+
+ async command void ReliableWait.waitTx(ieee154_timestamp_t *t0, uint32_t dt)
+ {
+ if (m_state != S_WAIT_OFF){
+ ASSERT(0);
+ return;
+ }
+ m_state = S_WAIT_TX;
+ call SymbolAlarm.startAt(*t0 - 16, dt); // subtract 12 symbols required for Tx calibration
+ }
+
+ async command void ReliableWait.waitBackoff(uint32_t dt)
+ {
+ if (m_state != S_WAIT_OFF){
+ ASSERT(0);
+ return;
+ }
+ m_state = S_WAIT_BACKOFF;
+ call SymbolAlarm.start(dt);
+ }
+
+ async event void SymbolAlarm.fired()
+ {
+ switch (m_state)
+ {
+ case S_WAIT_RX: m_state = S_WAIT_OFF; signal ReliableWait.waitRxDone(); break;
+ case S_WAIT_TX: m_state = S_WAIT_OFF; signal ReliableWait.waitTxDone(); break;
+ case S_WAIT_BACKOFF: m_state = S_WAIT_OFF; signal ReliableWait.waitBackoffDone(); break;
+ default: ASSERT(0); break;
+ }
+ }
+
+ async command void ReferenceTime.getNow(ieee154_timestamp_t* timestamp, uint16_t dt)
+ {
+ *timestamp = call SymbolAlarm.getNow() + dt;
+ }
+
+ async command uint32_t ReferenceTime.toLocalTime(const ieee154_timestamp_t* timestamp)
+ {
+ return *timestamp;
+ }
+
+}
--- /dev/null
+/*
+ * Copyright (c) 2008, Technische Universitaet Berlin
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * - Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * - 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.
+ * - Neither the name of the Technische Universitaet Berlin 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 COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ *
+ * - Revision -------------------------------------------------------------
+ * $Revision$
+ * $Date$
+ * @author Jan Hauer <hauer@tkn.tu-berlin.de>
+ * ========================================================================
+ */
+
+#ifndef __TKN154_platform_H
+#define __TKN154_platform_H
+
+/****************************************************
+ * The following constants define guard times on MicaZ.
+ * All values are in symbol time (1 symbol = 16 us)
+ */
+
+enum {
+ // the expected maximum time between calling a transmit() operation and
+ // the radio putting the first byte on the channel assuming no CSMA-CA
+ IEEE154_RADIO_TX_DELAY = 400,
+
+ // the expected maximum time between calling a receive() operation and the
+ // the radio actually being put in receive mode
+ IEEE154_RADIO_RX_DELAY = 400,
+
+ // defines at what time the MAC payload for a beacon frame is assembled before
+ // the next scheduled beacon transmission time; the value must be smaller than
+ // the beacon interval plus the time for preparing the Tx operation
+ BEACON_PAYLOAD_UPDATE_INTERVAL = 2500,
+};
+
+typedef uint32_t ieee154_timestamp_t;
+
+#endif
+
projects / tinyos-2.x.git / commitdiff