Matthew Sims / mbed

Lab 1 Program C

Dependents:   Lab1C

Fork of mbed by -deleted-

SPIHalfDuplex.h@20:029aa53d7323, 2010-06-03 (annotated)

Committer:
simon
Date:
Thu Jun 03 11:17:50 2010 +0000
Revision:
20:029aa53d7323
Child:
27:7110ebee3484
* Add SPISlave, SPIHalfDuplex, SerialHalfDuplex

 * Add I2C repeated start

 * Add ethernet set_link()

 * Add documentation for wait()

Who changed what in which revision?

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