SPI.h

00001 /* mbed Microcontroller Library - SPI
00002  * Copyright (c) 2010-2011 ARM Limited. All rights reserved. 
00003  */
00004 
00005 #ifndef MBED_SPI_H
00006 #define MBED_SPI_H
00007 
00008 #include "device.h"
00009 
00010 #if DEVICE_SPI
00011 
00012 #include "platform.h"
00013 #include "PinNames.h"
00014 #include "PeripheralNames.h"
00015 #include "Base.h"
00016 
00017 namespace mbed {
00018 
00019 /** A SPI Master, used for communicating with SPI slave devices
00020  *
00021  *  The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
00022  *
00023  *  Most SPI devices will also require Chip Select and Reset signals. These
00024  *  can be controlled using <DigitalOut> pins
00025  *
00026  * Example:
00027  * @code
00028  * // Send a byte to a SPI slave, and record the response
00029  *
00030  * #include "mbed.h"
00031  *
00032  * SPI device(p5, p6, p7); // mosi, miso, sclk
00033  *
00034  * int main() {
00035  *     int response = device.write(0xFF);
00036  * }
00037  * @endcode
00038  */ 
00039 class SPI : public Base {
00040 
00041 public:
00042 
00043     /** Create a SPI master connected to the specified pins
00044      *
00045      *  Pin Options:
00046      *    (5, 6, 7) or (11, 12, 13)
00047      *
00048      *  mosi or miso can be specfied as NC if not used
00049      *
00050      *  @param mosi SPI Master Out, Slave In pin
00051      *  @param miso SPI Master In, Slave Out pin
00052      *  @param sclk SPI Clock pin
00053      *  @param name (optional) A string to identify the object     
00054      */
00055     SPI(PinName mosi, PinName miso, PinName sclk, const char *name = NULL);
00056 
00057     /** Configure the data transmission format
00058      *
00059      *  @param bits Number of bits per SPI frame (4 - 16)
00060      *  @param mode Clock polarity and phase mode (0 - 3)
00061      *
00062      * @code
00063      * mode | POL PHA 
00064      * -----+--------     
00065      *   0  |  0   0 
00066      *   1  |  0   1
00067      *   2  |  1   0 
00068      *   3  |  1   1
00069      * @endcode
00070      */
00071     void format(int bits, int mode = 0);
00072 
00073     /** Set the spi bus clock frequency
00074      *
00075      *  @param hz SCLK frequency in hz (default = 1MHz)
00076      */
00077     void frequency(int hz = 1000000);
00078 
00079     /** Write to the SPI Slave and return the response
00080      *
00081      *  @param value Data to be sent to the SPI slave
00082      *
00083      *  @returns
00084      *    Response from the SPI slave
00085     */
00086     virtual int write(int value);
00087 
00088 
00089 #ifdef MBED_RPC
00090     virtual const struct rpc_method *get_rpc_methods();
00091     static struct rpc_class *get_rpc_class();
00092 #endif
00093 
00094 protected:
00095 
00096     SPIName _spi;
00097     
00098     void aquire(void);
00099     static SPI *_owner; 
00100     int _bits;
00101     int _mode;
00102     int _hz;
00103 
00104 };
00105 
00106 } // namespace mbed
00107 
00108 #endif
00109 
00110 #endif