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/

Diff: SimpleDMA.h

Revision:: 5:d9f46ef80e20
Parent:: 4:c3a84c6c432c
Child:: 7:d3be727fa9d2

--- a/SimpleDMA.h	Thu Dec 26 16:31:54 2013 +0000
+++ b/SimpleDMA.h	Sat Jan 04 14:42:33 2014 +0000
@@ -7,6 +7,7 @@
 
 #include "mbed.h"
 #include "SimpleDMA_KL25.h"
+#include "SimpleDMA_LPC1768.h"
 
 
 /**
@@ -42,8 +43,10 @@
 * @return - 0 on success
 */
 template<typename Type>
-int source(Type* pointer, bool autoinc, int size = sizeof(Type) * 8) {
-    return setAddress((uint32_t)pointer, size, true, autoinc);
+void source(Type* pointer, bool autoinc, int size = sizeof(Type) * 8) {
+    _source = (uint32_t)pointer;
+    source_inc = autoinc;
+    source_size = size;
 }
 
 /**
@@ -63,8 +66,10 @@
 * @return - 0 on success
 */
 template<typename Type>
-int destination(Type* pointer, bool autoinc, int size = sizeof(Type) * 8) {
-    return setAddress((uint32_t)pointer, size, false, autoinc);
+void destination(Type* pointer, bool autoinc, int size = sizeof(Type) * 8) {
+    _destination = (uint32_t)pointer;
+    destination_inc = autoinc;
+    destination_size = size;
 }
 
 /**
@@ -78,7 +83,9 @@
 * @param trig - trigger to use
 * @param return - 0 on success
 */
-int trigger(SimpleDMA_Trigger trig);
+void trigger(SimpleDMA_Trigger trig) {
+    _trigger = trig;
+}
 
 /**
 * Set the DMA channel
@@ -141,36 +148,33 @@
 #endif
 
 protected:
-int setAddress(uint32_t address, int wordsize, bool source, bool autoinc);
+int _channel;
+SimpleDMA_Trigger _trigger;
+uint32_t _source;
+uint32_t _destination;
+bool source_inc;
+bool destination_inc;
+uint8_t source_size;
+uint8_t destination_size;
 
-int _channel;
 bool auto_channel;
-uint32_t SAR, DAR, DSR, DCR;
-uint8_t CHCFG;
 
 //IRQ handlers
 FunctionPointer _callback;
 void irq_handler(void);
 
-static SimpleDMA *irq_owner[4];
+static SimpleDMA *irq_owner[DMA_CHANNELS];
+
+static void irq_handler0( void ); 
 
-static void irq_handler0( void ) {
-    if (irq_owner[0]!=NULL)
-        irq_owner[0]->irq_handler();
-}
-static void irq_handler1( void ) {
-    if (irq_owner[1]!=NULL)
-        irq_owner[1]->irq_handler();
-}
-static void irq_handler2( void ) {
-    if (irq_owner[2]!=NULL)
-        irq_owner[2]->irq_handler();
-}
-static void irq_handler3( void ) {
-    if (irq_owner[3]!=NULL)
-        irq_owner[3]->irq_handler();
-}
+#if DMA_IRQS > 1
+static void irq_handler1( void );
+static void irq_handler2( void );
+static void irq_handler3( void );
+#endif
 
+//Keep searching until we find a non-busy channel, start with lowest channel number
+int getFreeChannel(void);
 
 #ifdef RTOS_H
 osThreadId id;
@@ -178,17 +182,5 @@
     osSignalSet(id, 0x1);    
 }
 #endif
-
-//Keep searching until we find a non-busy channel, start with lowest channel number
-int getFreeChannel(void) {
-    int retval = 0;
-    while(1) {
-        if (!isBusy(retval))
-            return retval;
-        retval++;
-        if (retval >= DMA_CHANNELS)
-            retval = 0;
-    }  
-}
 };
 #endif
\ No newline at end of file