Rory Hand
my dependency on I2S
Diff: I2S.h
- Revision:
- 0:455d5826751b
- Child:
- 1:9dd9537d8ab6
--- /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