SPI.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_SPI_H
00023 #define MBED_SPI_H
00024 
00025 #include "platform.h"
00026 
00027 #if DEVICE_SPI
00028 
00029 #include "spi_api.h"
00030 
00031 namespace mbed {
00032 
00033 /** A SPI Master, used for communicating with SPI slave devices
00034  *
00035  * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
00036  *
00037  * Most SPI devices will also require Chip Select and Reset signals. These
00038  * can be controlled using <DigitalOut> pins
00039  *
00040  * Example:
00041  * @code
00042  * // Send a byte to a SPI slave, and record the response
00043  *
00044  * #include "mbed.h"
00045  *
00046  * SPI device(p5, p6, p7); // mosi, miso, sclk
00047  *
00048  * int main() {
00049  *     int response = device.write(0xFF);
00050  * }
00051  * @endcode
00052  */
00053 class SPI {
00054 
00055 public:
00056 
00057     /** Create a SPI master connected to the specified pins
00058      *
00059      * Pin Options:
00060      *  (5, 6, 7) or (11, 12, 13)
00061      *
00062      *  mosi or miso can be specfied as NC if not used
00063      *
00064      *  @param mosi SPI Master Out, Slave In pin
00065      *  @param miso SPI Master In, Slave Out pin
00066      *  @param sclk SPI Clock pin
00067      */
00068     SPI(PinName mosi, PinName miso, PinName sclk);
00069 
00070     /** Configure the data transmission format
00071      *
00072      *  @param bits Number of bits per SPI frame (4 - 16)
00073      *  @param mode Clock polarity and phase mode (0 - 3)
00074      *
00075      * @code
00076      * mode | POL PHA
00077      * -----+--------
00078      *   0  |  0   0
00079      *   1  |  0   1
00080      *   2  |  1   0
00081      *   3  |  1   1
00082      * @endcode
00083      */
00084     void format(int bits, int mode = 0);
00085 
00086     /** Set the spi bus clock frequency
00087      *
00088      *  @param hz SCLK frequency in hz (default = 1MHz)
00089      */
00090     void frequency(int hz = 1000000);
00091 
00092     /** Write to the SPI Slave and return the response
00093      *
00094      *  @param value Data to be sent to the SPI slave
00095      *
00096      *  @returns
00097      *    Response from the SPI slave
00098     */
00099     virtual int write(int value);
00100 
00101 protected:
00102     spi_t _spi;
00103 
00104     void aquire(void);
00105     static SPI *_owner;
00106     int _bits;
00107     int _mode;
00108     int _hz;
00109 };
00110 
00111 } // namespace mbed
00112 
00113 #endif
00114 
00115 #endif
00116