added rise/fall handler timing measurements

XMC_MBED/APP_InterruptIn/README.adoc

@@ -12,6 +12,19 @@ image::seriallog.png[]
 This example also uses MBED-OS queue functionality as well as UART1 on the XMC 
 Relax-Kit.
 
+The following screenshot shows the time it takes from the input event until
+event processing via an event queue. Here the event of the falling edge is
+queued as event in MBED-OS. It takes approximately 35ms until MBED-OS is ready
+to process this event (`fall_handler()`).
+
+image::fallhandler.png[]
+
+The next screenshot shows the timing when the routine is called from the ISR
+context (regular ISR processing). Here it takes approximately 0.3ms from the
+event until the `rise_handler()` (the ISR) is processed.
+
+image::rise_handler.png[]
+
 == Makefile Usage
 
 [source%nowrap, bash]
@@ -34,7 +47,7 @@ mbed compile -c -m XMC_4500_RELAX_KIT -t GCC_ARM -N main
 ----
 
 This creates several files in the BUILD directory where you can find the
-executables (bin, elf, hex ...).
+executable (bin, elf, hex ...).
 
 == Flashing