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RIOT/drivers/cc110x/include/cc110x_internal.h

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drivers/cc110x: Rewrite of the cc110x driver The cc110x driver has been re-written from scratch to overcome the limitations of the old driver. The main motivation of the rewrite was to achieve better maintainability by a detailed documentation, reduce the complexity and the overhead of the SPI communication with the device, and to allow to simultaneously use transceivers with different configuration regarding the used base band, the channel bandwidth, the modulation rate, and the channel map. Features of this driver include: - Support for the CC1100, CC1101, and the CC1100e sub-gigahertz transceivers. - Detailed documentation of every aspect of this driver. - An easy to use configuration API that allows setting the transceiver configuration (modulation rate, channel bandwidth, base frequency) and the channel map. - Fast channel hopping by pre-calibration of the channels during device configuration (so that no calibration is needed during hopping). - Simplified SPI communication: Only during start-up the MCU has to wait for the transceiver to be ready (for the power regulators and the crystal to stabilize). The old driver did this for every SPI transfer, which resulted in complex communication code. This driver will wait on start up for the transceiver to power up and then use RIOT's SPI API like every other driver. (Not only the data sheet states that this is fine, it also proved to be reliable in practise.) - Greatly reduced latency: The RTT on the old driver (@150 kbps data rate) was about 16ms, the new driver (@250 kbps data rate) has as RTT of ~3ms (depending on SPI clock and on CPU performance) (measured with ping6). - Increased reliability: The preamble size and the sync word size have been doubled compared to the old driver (preamble: 8 bytes instead of 4, sync word: 4 byte instead of 2). The new values are the once recommended by the data sheet for reliable communication. - Basic diagnostic during driver initialization to detect common issues as SPI communication issues and GDO pin configuration/wiring issues. - TX power configuration with netdev_driver_t::set() API-integration - Calls to netdev_driver_t::send() block until the transmission has completed to ease the use of the API (implemented without busy waiting, so that the MCU can enter lower power states or other threads can be executed).
2018-11-08 17:37:07 +01:00
/*
* Copyright (C) 2018 Otto-von-Guericke-Universität Magdeburg
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_cc110x
* @{
*
* @file
* @brief Internal functions of the CC110x transceiver driver
*
* @author Marian Buschsieweke <marian.buschsieweke@ovgu.de>
* @}
*/
#ifndef CC110X_INTERNAL_H
#define CC110X_INTERNAL_H
#include "cc110x_calibration.h"
#include "cc110x_communication.h"
#include "cc110x_constants.h"
#include "cc110x_netdev.h"
#include "cc110x_rx_tx.h"
#include "cc110x_settings.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Extract the device state from the status register value
*
* @param status Contents of the CC110x's status register
* @return The state encoded in @p status
*
* The status register contains the device state at the bits 1 - 3
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Format of the status byte
* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* |R|STATE| FIFO |
* +-+-+-+-+-+-+-+-+
*
* R = Chip Ready bit (0 = ready, 1 = power and crystal are not yet stable)
* STATE = The device state
* FIFO = Number of bytes available in RX FIFO or (in TX mode) number of free
* bytes
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Note: The FIFO has a size of 64 bytes. If more than 15 bytes are available
* for reading in the FIFO (or more than 15 bytes can be written in TX), the
* value will still show 15. This driver never uses this information, but
* accesses a dedicated register for that.
*/
static inline cc110x_state_t cc110x_state_from_status(uint8_t status)
{
return (cc110x_state_t)((status >> 4) & 0x7);
}
/**
* @brief Figure out of the transceiver is ready or still powering up
* @param status Contents of the CC110x's status register
* @retval 1 Transceiver is ready
* @retval 0 *NOT* ready, still powering up
*
* @see cc110x_state_from_status
*/
static inline int cc110x_is_ready_from_status(uint8_t status)
{
return (status & 0x80) ? 0: 1;
}
#ifdef __cplusplus
}
#endif
#endif /* CC110X_INTERNAL_H */
/** @} */