Introduction

SimpleDMA is a standard library for different DMA peripherals. Currently the LPC1768, KL46Z and KL25Z are supported. It provided one set of functions for different peripherals. It does not allow for usage of all the advanced functions, partially because the goal was to provide a simple interface, and partially because they are different for different microcontrollers.

Examples

Helloworld: http://mbed.org/users/Sissors/code/SimpleDMA_HelloWorld/

Example in a library (SPI): http://mbed.org/users/Sissors/code/RTOS_SPI/

SimpleDMA.h@0:d77ea45fa625, 2013-10-18 (annotated)

Committer:: Sissors
Date:: Fri Oct 18 07:44:42 2013 +0000
Revision:: 0:d77ea45fa625
Child:: 1:0b73b00bcee8

v0.1, KL25, no interrupt

Who changed what in which revision?

User	Revision	Line number	New contents of line
Sissors	0:d77ea45fa625	1	#ifndef SIMPLEDMA_H
Sissors	0:d77ea45fa625	2	#define SIMPLEDMA_H
Sissors	0:d77ea45fa625	3
Sissors	0:d77ea45fa625	4	#include "mbed.h"
Sissors	0:d77ea45fa625	5	#include "SimpleDMA_KL25.h"
Sissors	0:d77ea45fa625	6
Sissors	0:d77ea45fa625	7
Sissors	0:d77ea45fa625	8	/**
Sissors	0:d77ea45fa625	9	* SimpleDMA, DMA made simple! (Okay that was bad)
Sissors	0:d77ea45fa625	10	*
Sissors	0:d77ea45fa625	11	* A class to easily make basic DMA operations happen. Not all features
Sissors	0:d77ea45fa625	12	* of the DMA peripherals are used, but the main ones are: From and to memory
Sissors	0:d77ea45fa625	13	* and peripherals, either continiously or triggered
Sissors	0:d77ea45fa625	14	*/
Sissors	0:d77ea45fa625	15	class SimpleDMA {
Sissors	0:d77ea45fa625	16	public:
Sissors	0:d77ea45fa625	17	SimpleDMA(int channel = 0);
Sissors	0:d77ea45fa625	18
Sissors	0:d77ea45fa625	19	/**
Sissors	0:d77ea45fa625	20	* Set the source of the DMA transfer
Sissors	0:d77ea45fa625	21	*
Sissors	0:d77ea45fa625	22	* Autoincrement increments the pointer after each transfer. If the source
Sissors	0:d77ea45fa625	23	* is an array this should be true, if it is a peripheral or a single memory
Sissors	0:d77ea45fa625	24	* location it should be false.
Sissors	0:d77ea45fa625	25	*
Sissors	0:d77ea45fa625	26	* The source can be any pointer to any memory location. Automatically
Sissors	0:d77ea45fa625	27	* the wordsize is calculated depending on the type, if required you can
Sissors	0:d77ea45fa625	28	* also override this.
Sissors	0:d77ea45fa625	29	*
Sissors	0:d77ea45fa625	30	* @param pointer - pointer to the memory location
Sissors	0:d77ea45fa625	31	* @param autoinc - should the pointer be incremented by the DMA module
Sissors	0:d77ea45fa625	32	* @param size - size of the transfer (optional, generally can be omitted)
Sissors	0:d77ea45fa625	33	* @return - 0 on success
Sissors	0:d77ea45fa625	34	*/
Sissors	0:d77ea45fa625	35	template<typename Type>
Sissors	0:d77ea45fa625	36	int source(Type* pointer, bool autoinc, int size = sizeof(Type*)) {
Sissors	0:d77ea45fa625	37	return setMemory((uint32_t)pointer, size, true, autoinc);
Sissors	0:d77ea45fa625	38	}
Sissors	0:d77ea45fa625	39
Sissors	0:d77ea45fa625	40	/**
Sissors	0:d77ea45fa625	41	* Set the destination of the DMA transfer
Sissors	0:d77ea45fa625	42	*
Sissors	0:d77ea45fa625	43	* Autoincrement increments the pointer after each transfer. If the source
Sissors	0:d77ea45fa625	44	* is an array this should be true, if it is a peripheral or a single memory
Sissors	0:d77ea45fa625	45	* location it should be false.
Sissors	0:d77ea45fa625	46	*
Sissors	0:d77ea45fa625	47	* The destination can be any pointer to any memory location. Automatically
Sissors	0:d77ea45fa625	48	* the wordsize is calculated depending on the type, if required you can
Sissors	0:d77ea45fa625	49	* also override this.
Sissors	0:d77ea45fa625	50	*
Sissors	0:d77ea45fa625	51	* @param pointer - pointer to the memory location
Sissors	0:d77ea45fa625	52	* @param autoinc - should the pointer be incremented by the DMA module
Sissors	0:d77ea45fa625	53	* @param size - size of the transfer (optional, generally can be omitted)
Sissors	0:d77ea45fa625	54	* @return - 0 on success
Sissors	0:d77ea45fa625	55	*/
Sissors	0:d77ea45fa625	56	template<typename Type>
Sissors	0:d77ea45fa625	57	int destination(Type* pointer, bool autoinc, int size = sizeof(Type*)) {
Sissors	0:d77ea45fa625	58	return setMemory((uint32_t)pointer, size, false, autoinc);
Sissors	0:d77ea45fa625	59	}
Sissors	0:d77ea45fa625	60
Sissors	0:d77ea45fa625	61	/**
Sissors	0:d77ea45fa625	62	* Set the trigger for the DMA operation
Sissors	0:d77ea45fa625	63	*
Sissors	0:d77ea45fa625	64	* In SimpleDMA_[yourdevice].h you can find the names of the different triggers.
Sissors	0:d77ea45fa625	65	* Trigger_ALWAYS is defined for all devices, it will simply move the data
Sissors	0:d77ea45fa625	66	* as fast as possible. Used for memory-memory transfers. If nothing else is set
Sissors	0:d77ea45fa625	67	* that will be used by default.
Sissors	0:d77ea45fa625	68	*
Sissors	0:d77ea45fa625	69	* @param trig - trigger to use
Sissors	0:d77ea45fa625	70	* @param return - 0 on success
Sissors	0:d77ea45fa625	71	*/
Sissors	0:d77ea45fa625	72	int trigger(SimpleDMA_Trigger trig);
Sissors	0:d77ea45fa625	73
Sissors	0:d77ea45fa625	74	/**
Sissors	0:d77ea45fa625	75	* Start the transfer
Sissors	0:d77ea45fa625	76	*
Sissors	0:d77ea45fa625	77	* @param length - number of BYTES to be moved by the DMA
Sissors	0:d77ea45fa625	78	*/
Sissors	0:d77ea45fa625	79	int start(int length);
Sissors	0:d77ea45fa625	80
Sissors	0:d77ea45fa625	81	/**
Sissors	0:d77ea45fa625	82	* Set the DMA channel
Sissors	0:d77ea45fa625	83	*
Sissors	0:d77ea45fa625	84	* @param chan - DMA channel to use
Sissors	0:d77ea45fa625	85	*/
Sissors	0:d77ea45fa625	86	void channel(int chan);
Sissors	0:d77ea45fa625	87
Sissors	0:d77ea45fa625	88	/**
Sissors	0:d77ea45fa625	89	* Is the DMA channel busy
Sissors	0:d77ea45fa625	90	*
Sissors	0:d77ea45fa625	91	* @return - true if it is busy
Sissors	0:d77ea45fa625	92	*/
Sissors	0:d77ea45fa625	93	bool isBusy( void );
Sissors	0:d77ea45fa625	94
Sissors	0:d77ea45fa625	95
Sissors	0:d77ea45fa625	96
Sissors	0:d77ea45fa625	97
Sissors	0:d77ea45fa625	98
Sissors	0:d77ea45fa625	99	protected:
Sissors	0:d77ea45fa625	100	int setMemory(uint32_t address, int wordsize, bool source, bool autoinc);
Sissors	0:d77ea45fa625	101	int _channel;
Sissors	0:d77ea45fa625	102
Sissors	0:d77ea45fa625	103
Sissors	0:d77ea45fa625	104
Sissors	0:d77ea45fa625	105	};
Sissors	0:d77ea45fa625	106	#endif