I2SSlave.h

00001 /**
00002 * @author Daniel Worrall
00003 *
00004 * @section LICENSE
00005 *
00006 * Copyright (c) 2011 mbed
00007 *
00008 * Permission is hereby granted, free of charge, to any person obtaining a copy
00009 * of this software and associated documentation files (the "Software"), to deal
00010 * in the Software without restriction, including without limitation the rights
00011 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00012 * copies of the Software, and to permit persons to whom the Software is
00013 * furnished to do so, subject to the following conditions:
00014 *
00015 * The above copyright notice and this permission notice shall be included in
00016 * all copies or substantial portions of the Software.
00017 *
00018 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00019 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00020 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00021 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00022 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00023 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00024 * THE SOFTWARE.
00025 *
00026 * @section DESCRIPTION
00027 *    I2S port abstraction library h file for NXP LPC1768
00028 *
00029 */ 
00030 
00031 #include "mbed.h"
00032 #include "math.h"
00033 
00034 #ifndef __MBED_I2SSLAVE_H__
00035 #define __MBED_I2SSLAVE_H__
00036 
00037 extern FunctionPointer akjnh3489v8ncv;
00038 
00039 /** I2S class defined on the LPC1768 port
00040  *
00041  */
00042 class I2SSlave{
00043 
00044     public:
00045         //Constructor
00046         /** Create an I2S object
00047          *
00048          * @param tx_sda Transmitter serial data line
00049          * @param tx_ws Transmitter word select line
00050          * @param clk Shared transmitter/receiver clock line
00051          * @param rx_sda Receiver serial data line
00052          * @param rx_ws Receiver word select line
00053          */
00054         I2SSlave(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws);
00055         /** Set the data transmission format
00056          *
00057          * @param bit Set the number of bits per write
00058          * @param mode Set STEREO (0) or MONO (1) mode
00059          */
00060         void format(int bit, bool mode);
00061         /** Write a buffer to the I2S port
00062          *
00063          * @param buffer Address of buffer to pass to I2S port
00064          * @param from Start position in buffer to read from
00065          * @param length Length of buffer (MUST not exceed 8 words, each 32 bits long)
00066          *
00067          * Note: sending 8 words to the TXFIFO will trigger an interrupt!
00068          */
00069         void write(int* buffer, int from,  int length);
00070         /** Activate I2S port for data streaming 
00071          *
00072          * @param mode Mode to enable - NONE, TRANSMIT only, RECEIVE only, BOTH
00073          * Enables tx/rx interrupts
00074          */
00075         void start(int mode);
00076         /** Deactivate I2S port from data streaming 
00077          *
00078          * Disable all interrupts
00079          */
00080         void stop(void);
00081         /** Load receive FIFO data into receiver buffer
00082          *
00083          */
00084         void read(void);
00085         /** Attach a void/void function or void/void static memeber function to an interrupt generated by the I2SxxFIFOs
00086          *
00087          * @param function Function to attach
00088          *
00089          * <code> myI2sObject.attach(&myfunction); </code>
00090          * OR <code> myI2sObject.attach(&myClass::myStaticMemberFunction); </code>
00091          */
00092         void attach(void(*fptr)(void)){
00093             akjnh3489v8ncv.attach(fptr);
00094         }
00095         /** Attach a nonstatic void/void member function to an interrupt generated by the I2SxxFIFOs
00096          *
00097          * @param tptr Object pointer
00098          * @param mptr Member function pointer
00099          *
00100          * e.g. <code>myI2sObject.attach(&myObject, &myClass::myNonstaticMemberFunction); </code>where myObject is an object of myClass
00101          */
00102         template<typename T>
00103         void attach(T *tptr, void(T::*mptr)(void)){
00104             akjnh3489v8ncv.attach(tptr, mptr);
00105         }
00106         /** Return contents of I2S status register
00107          *
00108          * @returns Content of I2SSTATE register
00109          *
00110          * bit0: receive/transmit interrupt active
00111          * bit1: receive/transmit DMA request 1
00112          * bit2: receive/transmit DMA request 2
00113          * bit[11:8]: receive FIFO level
00114          * bit[19:16]: transmit FIFO level
00115          */
00116         int status(void);
00117         
00118         //Receiver buffer
00119         int rxBuffer[4];
00120         //defines
00121         #define STEREO  0
00122         #define MONO    1
00123         
00124         #define I2SFIFO_EMPTY    0
00125         #define I2SFIFO_FULL     8
00126         
00127         #define RAM_LENGTH  1024
00128         #define RAM_LIMIT   (RAM_LENGTH - 1) 
00129         #define PTR_MAX     ((RAM_LENGTH / 8) - 1)
00130         
00131         #define NONE        0
00132         #define TRANSMIT    1
00133         #define RECEIVE     2
00134         #define BOTH        3
00135 
00136     private:        
00137         /** I2S intitalize function
00138          *
00139          * @param tx_sda Transmitter serial data line
00140          * @param tx_ws Transmitter word select line
00141          * @param clk Shared transmitter/receiver clock line
00142          * @param rx_sda Receiver serial data line
00143          * @param rx_ws Receiver word select line
00144          * @return Returns 0 for successful initialisation, -1 for an error
00145          */
00146         int initialize_(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws);
00147         /** Set internal clock divide by rate
00148          *
00149          * @param divideBy Divide by 1, 2, 4 or 8
00150          */
00151         void setClocks_(int divideBy);
00152         /** Set up the pins on the processor itself
00153          *
00154          * @param tx_sda Transmitter serial data line
00155          * @param tx_ws Transmitter word select line
00156          * @param clk Shared transmitter/receiver clock line
00157          * @param rx_sda Receiver serial data line
00158          * @param rx_ws Receiver word select line
00159          */
00160         void setPins_(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws);
00161         /** Set the data transmission format 
00162          *
00163          * @param bit Set the number of bits per write
00164          * @param mode Set STEREO (0) or MONO (1) mode
00165          */
00166         void format_(int bit, bool mode);
00167         /** Set slave mode
00168          *
00169          */
00170         void modeConfig_(void);
00171         /** Store PinName values
00172          * 
00173          * @param tx_sda Transmitter serial data line
00174          * @param tx_ws Transmitter word select line
00175          * @param clk Shared transmitter/receiver clock line
00176          * @param rx_sda Receiver serial data line
00177          * @param rx_ws Receiver word select line
00178          */
00179         void storePins_(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws);
00180         //variables
00181         int bit_;
00182         bool mode_;
00183         PinName tx_sda_; 
00184         PinName tx_ws_; 
00185         PinName clk_;
00186         PinName rx_sda_;
00187         PinName rx_ws_;
00188 };
00189 
00190 #endif /*__MBED_I2S_H__*/