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 /* Class: SPI
00020  *  A SPI Master, used for communicating with SPI slave devices
00021  *
00022  * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
00023  *
00024  * Most SPI devices will also require Chip Select and Reset signals. These
00025  * can be controlled using <DigitalOut> pins
00026  *
00027  * Example:
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  */ 
00038 class SPI : public Base {
00039 
00040 public:
00041 
00042     /* Constructor: SPI
00043      *  Create a SPI master connected to the specified pins
00044      *
00045      * Variables:
00046      *  mosi - SPI Master Out, Slave In pin
00047      *  miso - SPI Master In, Slave Out pin
00048      *  sclk - SPI Clock pin
00049      *  name - (optional) A string to identify the object     
00050      *
00051      * Pin Options:
00052      *  (5, 6, 7) or (11, 12, 13)
00053      *
00054      *  mosi or miso can be specfied as NC if not used
00055      */
00056     SPI(PinName mosi, PinName miso, PinName sclk, const char *name = NULL);
00057 
00058     /* Function: format
00059      *  Configure the data transmission format
00060      *
00061      * Variables:
00062      *  bits - Number of bits per SPI frame (4 - 16)
00063      *  mode - Clock polarity and phase mode (0 - 3)
00064      *
00065      * > mode | POL PHA 
00066      * > -----+--------  
00067      * >   0  |  0   0 
00068      * >   1  |  0   1
00069      * >   2  |  1   0 
00070      * >   3  |  1   1
00071      */
00072     void format(int bits, int mode = 0);
00073 
00074     /* Function: frequency
00075      *  Set the spi bus clock frequency
00076      *
00077      * Variables:
00078      *  hz - SCLK frequency in hz (default = 1MHz)
00079      */
00080     void frequency(int hz = 1000000);
00081 
00082     /* Function: write
00083      *  Write to the SPI Slave and return the response
00084      *
00085      * Variables:
00086      *  value - Data to be sent to the SPI slave
00087      *  returns - Response from the SPI slave
00088     */
00089     virtual int write(int value);
00090 
00091 
00092 #ifdef MBED_RPC
00093     virtual const struct rpc_method *get_rpc_methods();
00094     static struct rpc_class *get_rpc_class();
00095 #endif
00096 
00097 protected:
00098 
00099     SPIName _spi;
00100     
00101     void aquire(void);
00102     static SPI *_owner; 
00103     int _bits;
00104     int _mode;
00105     int _hz;
00106 
00107 };
00108 
00109 } // namespace mbed
00110 
00111 #endif
00112 
00113 #endif