added a lot of comments to better describe the funcionality of the applications

XMC_MBED/APP_AnalogOut/main.cpp

@@ -18,28 +18,36 @@
 #include "mbed.h"
 
 /******************************************************************** Globals */
-AnalogOut aout(P14_8);
+/* create an object of class AnalogOut: "aout"
+   see drivers/AnalogOut.h
+   the parameter P14_8 is declared in
+   targets/TARGET_Infineon/TARGET_XMC4XXX/TARGET_XMC4500/PinNames.h
+*/
+AnalogOut aout (P14_8);
 
 /****************************************************************** Functions */
-
 /**
  * Main Function
  */
-int main() {
+int main (void)
+{
 	const double pi = 3.141592653589793238462;
 	const double amplitude = 0.4f;
 	const double offset = 65535;
 	double rads = 0.0;
 	uint16_t sample = 0;
 
-    while(1) {
+	while (1) {
 		/* Generate Sinus */
 		for (int i = 0; i < 360; i++) {
 			rads = (pi * i) / 180.0f;
-            sample = (uint16_t)(amplitude * (offset * (cos(rads + pi))) + offset);
-            aout.write_u16(sample);
+			sample = (uint16_t) (amplitude * (offset * (cos (rads + pi))) + offset);
+			/* invoke the method .write_u16() on the object aout
+			   see drivers/AnalogOut.h
+			   this method outputs an anlog value on P14_8 using the DAC
+			*/
+			aout.write_u16 (sample);
 		}
 	}
 }
-
 /*EOF*/

XMC_MBED/APP_BLINKY/main.cpp

@@ -18,20 +18,29 @@
 #include "mbed.h"
 
 /******************************************************************** Globals */
-DigitalOut led(LED1);
+/* create an object from class Digitalout: "led"
+   see drivers/DigitalOut.h
+   the parameter LED1 is declared in
+   targets/TARGET_Infineon/TARGET_XMC4XXX/TARGET_XMC4500/PinNames.h
+*/
+DigitalOut led (LED1);
 
 /****************************************************************** Functions */
-
 /**
  * Main Function
  */
-int main() {
-
+int main (void)
+{
 	/* Toggle LED1  */
 	while (1) {
+		/* overload the operator = using "operator="
+		   see drivers/DigitalOut.h
+		*/
 		led = !led;
-        wait(0.5);
+		/* call the function wait() - wait fro a number of seconds (ms resolution)
+		   see platform/mbed_wait_api.cpp
+		*/
+		wait (0.5);
 	}
 }
-
 /*EOF*/

XMC_MBED/APP_InterruptIn/main.cpp

@@ -19,8 +19,23 @@
 #include "rtos.h"
 
 /***************************************************************** Prototypes */
+/* create an object of class InterruptIn: "sw"
+   see drivers/InterruptIn.h
+   SW2 is defined in
+   targets/TARGET_Infineon/TARGET_XMC4XXX/TARGET_XMC4500/PinNames.h
+*/
 InterruptIn sw (SW2);       // BUTTON2 = P1.15
+/* create an object of class DigitalOut: "led1"
+   see drivers/DigitalOut.h
+   LED1 is defined in
+   targets/TARGET_Infineon/TARGET_XMC4XXX/TARGET_XMC4500/PinNames.h
+*/
 DigitalOut led1 (LED1);     // LED1 = P1.1
+/* create an object of class Serial: "device"
+   see drivers/Serial.h
+   P0_1 and P0_0 are defined in
+   targets/TARGET_Infineon/TARGET_XMC4XXX/TARGET_XMC4500/PinNames.h
+*/
 Serial device (P0_1, P0_0); // UART1 -> Tx = P0.1, Rx = P0.0
 
 /****************************************************************** Callbacks */
@@ -29,7 +44,10 @@ Serial device (P0_1, P0_0); // UART1 -> Tx = P0.1, Rx = P0.0
  */
 void rise_handler (void)
 {
-	// Toggle LED1
+	/* ovverride the = operator using "operator ="
+	   see drivers/DigitalOut.h
+	   -> toggle LED1
+	*/
 	led1 = !led1;
 }
 
@@ -38,27 +56,44 @@ void rise_handler (void)
  */
 void fall_handler (void)
 {
-	// output message via UART1
+	/* output a message via UART1, in partzicular the thread id is output
+	   using the .gettid() method of the current thread
+	   see rtos/Thread.cpp
+	*/
 	device.printf ("fall_handler in context %p\r\n", Thread::gettid());
-	// Toggle LED1
+	/* toggle LED1 */
 	led1 = !led1;
 }
 
 /****************************************************************** Functions */
-
 /**
  * Main Function
  */
 int main (void)
 {
-	// Request the shared queue
+	/* request the shared queue to the OS
+	   see events mbed_event_queue.cpp
+	*/
 	EventQueue *queue = mbed_event_queue();
-	// Output message via UART1
+	/* output a message via the device (here UART1) to that end the .printf()
+	   method of platform/Stream.h is invoked, the function will output the
+	   thread id of the main thread using the .gettid() method
+	   see rtos/Thread.cpp
+	*/
 	device.printf ("Starting in context %p\r\n", Thread::gettid());
-
-	// The 'rise' handler will execute in the IRQ context
+	/* the 'rise_handler()' callback function will execute in the IRQ context
+	   it is installed using the method .rise() and activated when a rising edge
+	   occurs on the input
+	   see drivers/InterruptIn.h
+	*/
 	sw.rise (rise_handler);
-	// The 'fall' handler will execute in the context of the shared queue thread
+	/* The 'fall_handler()' callback will execute in the context of the shared
+	   queue thread - it is installed using the .fall() method see
+	   drivers/InterruptIn.h and activated when a falling edge on the input
+	   is detected - whenever this occurs it is put into a general queue to
+	   the OS see events/mbed_shared_queues.h
+	   the fall_handler() will execute as a separate thread
+	*/
 	sw.fall (queue->event (fall_handler));
 }
 /*! EOF */

XMC_MBED/README.adoc

@@ -10,6 +10,11 @@ main mbed project hosted on github at https://github.com/mbed-Infineon-XMC/mbed-
 The example applications are obtained from https://github.com/mbed-Infineon-XMC?tab=repositories[https://github.com/mbed-Infineon-XMC?tab=repositories] and are 
 structured in folders named like `APP_XXX`.
 
+[TIP]
+Checkout the comments in the main.cpp files of every application - these 
+examples are heavily commented and refer to the respective files where the 
+classes, methods and definitions are found.
+
 ## Import the project
 
 ```