Matthew Sims / mbed

Lab 1 Program C

Dependents:   Lab1C

Fork of mbed by -deleted-

SPIHalfDuplex.h@30:3991a86798e3, 2012-01-04 (annotated)

Committer:
emilmont
Date:
Wed Jan 04 16:29:47 2012 +0000
Revision:
30:3991a86798e3
Parent:
27:7110ebee3484
Child:
43:aff670d0d510
Add latest ARM GCC toolchain build

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 27:7110ebee3484 1 /* mbed Microcontroller Library - SPIHalfDuplex
emilmont 27:7110ebee3484 2 * Copyright (c) 2010-2011 ARM Limited. All rights reserved.
simon 20:029aa53d7323 3 */
simon 20:029aa53d7323 4
simon 20:029aa53d7323 5 #ifndef MBED_SPIHALFDUPLEX_H
simon 20:029aa53d7323 6 #define MBED_SPIHALFDUPLEX_H
simon 20:029aa53d7323 7
emilmont 27:7110ebee3484 8 #include "device.h"
emilmont 27:7110ebee3484 9
emilmont 30:3991a86798e3 10 #if DEVICE_SPI
emilmont 27:7110ebee3484 11
simon 20:029aa53d7323 12 #include "SPI.h"
simon 20:029aa53d7323 13
simon 20:029aa53d7323 14 namespace mbed {
simon 20:029aa53d7323 15
simon 20:029aa53d7323 16 /* Class: SPIHalfDuplex
simon 20:029aa53d7323 17 * A SPI half-duplex master, used for communicating with SPI slave devices
simon 20:029aa53d7323 18 * over a shared data line.
simon 20:029aa53d7323 19 *
simon 20:029aa53d7323 20 * The default format is set to 8-bits for both master and slave, and a
simon 20:029aa53d7323 21 * clock frequency of 1MHz
simon 20:029aa53d7323 22 *
simon 20:029aa53d7323 23 * Most SPI devies will also require Chip Select and Reset signals. These
simon 20:029aa53d7323 24 * can be controlled using <DigitalOut> pins.
simon 20:029aa53d7323 25 *
simon 20:029aa53d7323 26 * Although this is for a shared data line, both MISO and MOSI are defined,
simon 20:029aa53d7323 27 * and should be tied together externally to the mbed. This class handles
simon 20:029aa53d7323 28 * the tri-stating of the MOSI pin.
simon 20:029aa53d7323 29 *
simon 20:029aa53d7323 30 * Example:
simon 20:029aa53d7323 31 * > // Send a byte to a SPI half-duplex slave, and record the response
simon 20:029aa53d7323 32 * >
simon 20:029aa53d7323 33 * > #include "mbed.h"
simon 20:029aa53d7323 34 * >
simon 20:029aa53d7323 35 * > SPIHalfDuplex device(p5, p6, p7) // mosi, miso, sclk
simon 20:029aa53d7323 36 * >
simon 20:029aa53d7323 37 * > int main() {
simon 20:029aa53d7323 38 * > int respone = device.write(0xAA);
simon 20:029aa53d7323 39 * > }
simon 20:029aa53d7323 40 */
simon 20:029aa53d7323 41
simon 20:029aa53d7323 42 class SPIHalfDuplex : public SPI {
simon 20:029aa53d7323 43
simon 20:029aa53d7323 44 public:
simon 20:029aa53d7323 45
simon 20:029aa53d7323 46 /* Constructor: SPIHalfDuplex
simon 20:029aa53d7323 47 * Create a SPI half-duplex master connected to the specified pins
simon 20:029aa53d7323 48 *
simon 20:029aa53d7323 49 * Variables:
simon 20:029aa53d7323 50 * mosi - SPI Master Out, Slave In pin
simon 20:029aa53d7323 51 * miso - SPI Master In, Slave Out pin
simon 20:029aa53d7323 52 * sclk - SPI Clock pin
simon 20:029aa53d7323 53 * name - (optional) A string to identify the object
simon 20:029aa53d7323 54 *
simon 20:029aa53d7323 55 * Pin Options:
simon 20:029aa53d7323 56 * (5, 6, 7) or (11, 12, 13)
simon 20:029aa53d7323 57 *
simon 20:029aa53d7323 58 * mosi or miso can be specfied as NC if not used
simon 20:029aa53d7323 59 */
simon 20:029aa53d7323 60 SPIHalfDuplex(PinName mosi, PinName miso, PinName sclk,
simon 20:029aa53d7323 61 const char *name = NULL);
simon 20:029aa53d7323 62
simon 20:029aa53d7323 63 #if 0 // Inherited from SPI - documentation only
simon 20:029aa53d7323 64 /* Function: format
simon 20:029aa53d7323 65 * Configure the data transmission format
simon 20:029aa53d7323 66 *
simon 20:029aa53d7323 67 * Variables:
simon 20:029aa53d7323 68 * bits - Number of bits per SPI frame (4 - 16)
simon 20:029aa53d7323 69 * mode - Clock polarity and phase mode (0 - 3)
simon 20:029aa53d7323 70 *
simon 20:029aa53d7323 71 * > mode | POL PHA
simon 20:029aa53d7323 72 * > -----+--------
simon 20:029aa53d7323 73 * > 0 | 0 0
simon 20:029aa53d7323 74 * > 1 | 0 1
simon 20:029aa53d7323 75 * > 2 | 1 0
simon 20:029aa53d7323 76 * > 3 | 1 1
simon 20:029aa53d7323 77 */
simon 20:029aa53d7323 78 void format(int bits, int mode = 0);
simon 20:029aa53d7323 79
simon 20:029aa53d7323 80 /* Function: frequency
simon 20:029aa53d7323 81 * Set the spi bus clock frequency
simon 20:029aa53d7323 82 *
simon 20:029aa53d7323 83 * Variables:
simon 20:029aa53d7323 84 * hz - SCLK frequency in hz (default = 1MHz)
simon 20:029aa53d7323 85 */
simon 20:029aa53d7323 86 void frequency(int hz = 1000000);
simon 20:029aa53d7323 87 #endif
simon 20:029aa53d7323 88
simon 20:029aa53d7323 89 /* Function: write
simon 20:029aa53d7323 90 * Write to the SPI Slave and return the response
simon 20:029aa53d7323 91 *
simon 20:029aa53d7323 92 * Variables:
simon 20:029aa53d7323 93 * value - Data to be sent to the SPI slave
simon 20:029aa53d7323 94 * returns - Response from the SPI slave
simon 20:029aa53d7323 95 */
simon 20:029aa53d7323 96 virtual int write(int value);
simon 20:029aa53d7323 97
simon 20:029aa53d7323 98 /* Function: slave_format
simon 20:029aa53d7323 99 * Set the number of databits expected from the slave, from 4-16
simon 20:029aa53d7323 100 *
simon 20:029aa53d7323 101 * Variables:
simon 20:029aa53d7323 102 * sbits - Number of expected bits in the slave response
simon 20:029aa53d7323 103 */
simon 20:029aa53d7323 104 void slave_format(int sbits);
simon 20:029aa53d7323 105
simon 20:029aa53d7323 106 protected:
simon 20:029aa53d7323 107 PinName _mosi;
simon 20:029aa53d7323 108 PinName _miso;
simon 20:029aa53d7323 109 int _sbits;
simon 20:029aa53d7323 110
simon 20:029aa53d7323 111 }; // End of class
simon 20:029aa53d7323 112
simon 20:029aa53d7323 113 } // End of namespace mbed
simon 20:029aa53d7323 114
simon 20:029aa53d7323 115 #endif
emilmont 27:7110ebee3484 116
emilmont 27:7110ebee3484 117 #endif