Adapted to work with the LPC4088 Experiment Base Board
Dependents: lpc4088_ebb_ptp Algorithm-testing
Fork of I2S by
Diff: I2S.h
- Revision:
- 0:455d5826751b
diff -r 000000000000 -r 455d5826751b I2S.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/I2S.h Wed Sep 19 10:53:33 2012 +0000 @@ -0,0 +1,316 @@ +/** +* @author Giles Barton-Owen +* +* @section LICENSE +* +* Copyright (c) 2012 mbed +* +* Permission is hereby granted, free of charge, to any person obtaining a copy +* of this software and associated documentation files (the "Software"), to deal +* in the Software without restriction, including without limitation the rights +* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +* copies of the Software, and to permit persons to whom the Software is +* furnished to do so, subject to the following conditions: +* +* The above copyright notice and this permission notice shall be included in +* all copies or substantial portions of the Software. +* +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +* THE SOFTWARE. +* +* @section DESCRIPTION +* A I2S library for the LPC1768's built-in I2S peripheral +* +*/ + +#include "mbed.h" +#include "math.h" + +#ifndef I2S_H +#define I2S_H + +#define I2S_TRANSMIT 0 +#define I2S_RECEIVE 1 + +#define I2S_MASTER 0 +#define I2S_SLAVE 1 + +#define I2S_STEREO 0 +#define I2S_MONO 1 + +#define I2S_MUTED 1 +#define I2S_UNMUTED 0 + +#define I2S_4WIRE 1 +#define I2S_3WIRE 0 + +/** A class to play give access to the I2S library + */ + +class I2S +{ + +public: + + /** Create a I2S instance + * + * @param rxtx Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE) + * @param sd The serial data pin + * @param ws The word select pin + * @param clk The clock pin + */ + I2S(bool rxtx, PinName sd, PinName ws, PinName clk); + + /** Create a I2S instance: Only with the serial data line set. Won't really do much. + * + * @param rxtx Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE) + * @param sd The serial data pin + */ + I2S(bool rxtx, PinName sd); + + + /** Create a I2S instance: Only with serial data line and word select. + * + * @param rxtx Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE) + * @param sd The serial data pin + * @param ws The word select pin + */ + I2S(bool rxtx, PinName sd, PinName ws); + + + + /** Create a I2S instance: Only with serial data line. Four wire mode means this is functional + * + * @param rxtx Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE) + * @param sd The serial data pin + * @param fourwiremode True means the peripheral is in 4-wire mode. It borrows WS and CLK from the other half + */ + I2S(bool rxtx, PinName sd, bool fourwiremode); + + /** Create a I2S instance: Only with serial data line and word select line. Four wire mode means this is functional + * + * @param rxtx Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE) + * @param sd The serial data pin + * @param ws The word select pin + * @param fourwiremode True means the peripheral is in 4-wire mode. It borrows WS and CLK from the other half + */ + I2S(bool rxtx, PinName sd, PinName ws, bool fourwiremode); + + /** Destroy the I2S instance + */ + ~I2S(); + + /** Write to the FIFO + * + * @param buf[] The buffer of values to write: are bit stuffed in fours + * @param len The number of chars to write + */ + void write(char buf[], int len); + + /** Write to the FIFO + * + * @param buf[] The buffer of values to write: are bit stuffed automatically + * @param len The number of chars to write + */ + void write(int buf[], int len); + + /** Read the FIFOs contents + * + * @return The buffers value. + */ + int read(); + + /** Read from the FIFO + * + * @param buf[] The buffer of values to read: raw bit shifted + * @param len The number of chars to read + */ + void read(char buf[], int len); + + /** Read from the FIFO + * + * @param buf[] The buffer of values to read: sorted to just values + * @param len The number of chars to read + */ + void read(int buf[], int len); + + /** Get the maximum number of points of data the FIFO could store + * + * @return The number of points + */ + int max_fifo_points(); + /** Switch the peripheral on and off + * + * @param pwr Power status + */ + void power(bool pwr); + + /** Switch the peripheral between master and slave + * + * @param mastermode The peripherals master/slave status (I2S_MASTER/I2S_SLAVE) + */ + void masterslave(bool mastermode); + + /** Switch the peripheral between different wordsizes + * + * @param words The number of bits per word: 8,16,32 + */ + void wordsize(int words); + + /** Define the mclk frequency + * + * @param freq The frequency desired for the mclk + */ + void mclk_freq(int freq); + + /** Define the sample rate + * + * @param freq The desired sample rate frequency + */ + void frequency(int freq); + + /** Set the level that the fifo interrupts at + * + * @param level A number between 0 and 7 at which the fifo interrupts + */ + void set_interrupt_fifo_level(int level); + + /** Get the current FIFO level + * + * @return A number between 0 and 7 the FIFO is currently at + */ + int fifo_level(); + + /** Get the current number of samples in the FIFO + * + * @return A number showing how many samples are in the FIFO + */ + int fifo_points(); + + /** Set whether the peripheral is in stereo or mono mode: in mono the perifpheral sends out the same data twice + * + * @param stereomode Whether the peripheral is in stereo or mono: I2S_STEREO/I2S_MONO + */ + void stereomono(bool stereomode); + + /** Mute the peripheral + * + */ + void mute(); + + /** Set the mute status of the peripheral + * + * @param mute_en Set whether the mute is enabled + */ + void mute(bool mute_en); + + /** Stop the peripheral + * + */ + void stop(); + + /** Start the peripheral + * + */ + void start(); + + /** Check the Clock and Pin setup went according to plan + * + * @return Setup okay? + */ + bool setup_ok(); + + /** Attach a function to be called when the FIFO triggers + * + * @param fptr A pointer to the function to be called + */ + void attach(void (*fptr)(void)) + { + if (_rxtx == I2S_TRANSMIT) + { + I2STXISR.attach(fptr); + txisr = true; + } + else + { + I2SRXISR.attach(fptr); + rxisr = true; + } + } + + /** Attach a member function to be called when the FIFO triggers + * + * @param tptr A pointer to the instance of the class + * @param mptr A pointer to the member function + */ + template<typename T> + void attach(T *tptr, void (T::*mptr)(void)) + { + if (_rxtx == I2S_TRANSMIT) + { + I2STXISR.attach(tptr, mptr); + txisr = true; + } + else + { + I2SRXISR.attach(tptr, mptr); + rxisr = true; + } + } + +private: + + void mclk_enable(bool mclk_en); + + void write_registers(); + + void pin_setup(); + + void fraction_estimator(float in, int * num, int * den); + + float mod(float in); + + void defaulter(); + + PinName _sd, _ws, _clk, _mclk; + bool ws_d, clk_d, mclk_d; + bool _rxtx; + bool pwr; + bool master; + int wordwidth; + char wordwidth_code; + bool mclk_en; + int mclk_frequency; + int freq; + bool stereo; + bool muted; + bool stopped; + int interrupt_fifo_level; + int pin_setup_err; + int reg_write_err; + bool deallocating; + int old_freq; + + bool fourwire; + + int old_pre_num; + int old_pre_den; + int old_bitrate_div; + static void _i2sisr(void); + + static FunctionPointer I2STXISR; + static FunctionPointer I2SRXISR; + + static bool txisr; + static bool rxisr; + + void write(int bufr[], int bufl[], int len); + void read(int bufr[], int bufl[], int len); +}; + +#endif