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 ******************** (C) COPYRIGHT 2010 NXPSemiconductors *******************
 * @file    NVIC\Priority\abstract.txt 
 * @author  NXP MCU SW Application Team
 * @version 2.0
 * @date    
 * @brief   Description of the NVIC Priority example.
 ******************************************************************************
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * products. This software is supplied "AS IS" without any warranties.
 * NXP Semiconductors assumes no responsibility or liability for the
 * use of the software, conveys no license or title under any patent,
 * copyright, or mask work right to the product. NXP Semiconductors
 * reserves the right to make changes in the software without
 * notification. NXP Semiconductors also make no representation or
 * warranty that such application will be suitable for the specified
 * use without further testing or modification.
 ******************************************************************************
  
@Example description:
	Purpose:
		This example describes how to configure NVIC priority grouping for testing 
		tail-chaining/Late-arriving interrupt mode.
	Process:
		This example uses 2 external interrupt 0 and 3 as IRQ channels.
		Setting "INT_MODE" macro to chose interrupt mode test.
			- INT_MODE = 0: Tail-chainning interrupt testing
			EXT0 is assigned group-priority = 0, sub-priority = 2
			EXT3 is assigned group-priority = 0, sub-priority = 1
			Two IRQ channels has same group.So, new ISR can not pre-empt previous interrupt 
			when it's executing even if new ISR has higher priority than curren ISR
			- INT_MODE = 1: Late-arriving interrupt testing.
			EXT0 is assigned group-priority = 0, sub-priority = 0
			EXT3 is assigned group-priority = 1, sub-priority = 0
			EXT0 has higher group-priority than EXT3, so EXT0 can pre-empt EXT3 when it's executing
		
		In this example, EXT0 occurs when pressing button INT0. 
		EXT0 interrupt will blink LED P1.29 10 times.
		EXT3 occurs when turning ADC potentiometer until pull-down GPIO P0.25 pin (ADC0.2). 
		EXT3 interrupt will blink LED P1.28 10 times
			
					
@Directory contents:
	\EWARM: includes EWARM (IAR) project and configuration files
	\Keil:	includes RVMDK (Keil)project and configuration files 
	
	lpc17xx_libcfg.h: Library configuration file - include needed driver library for this example 
	makefile: Example's makefile (to build with GNU toolchain)
	nvic_priority.c: Main program

@How to run:
	Hardware configuration:		
		This example was tested only on:
			Keil MCB1700 with LPC1768 vers.1
				These jumpers must be configured as following:
				- VDDIO: ON
				- VDDREGS: ON 
				- VBUS: ON
				- INT0: ON
				- Remain jumpers: OFF
	
	Running mode:
		This example can run on RAM/ROM mode.
					
		Note: If want to burn hex file to board by using Flash Magic, these jumpers need
		to be connected:
			- MCB1700 with LPC1768 ver.1:
				+ RST: ON
				+ ISP: ON
			- IAR LPC1768 KickStart vers.A:
				+ RST_E: ON
				+ ISP_E: ON
		
		(Please reference "LPC1000 Software Development Toolchain" - chapter 4 "Creating and working with
		LPC1000CMSIS project" for more information)
	
	Step to run:
		- Step 1: Build example.
		- Step 2: Burn hex file into board (if run on ROM mode)
		- Step 3: Configure hardward as above instruction
		- Step 4: Run example
				  - Test tail-chaining interrupt mode:
				  	+ Hit INT0 button to generate EXT0. Led P1.29 will blink 10 times
				  	When P1.29 is blinking, turn ADC potentiometer and see if EXT3 pre-empt EXT0 or not.
				  	When EXT0 executes finised, EXT3 will bink led P1.28 10 times.
				  - Test late-arriving interrupt mode:
				  	+ Turn ADC potentiometer to generate EXT3, Led P1.28 will blink 10 times.
				  	When P1.28 is blinking, press INT0 button to see EXT0 pre-empt EXT3.
				  	Led P1.29 will blink instead led P1.28. After P1.29 blink 10 times, P1.28 continues
				  	blink remain times.
					
			
		(Pls see "LPC17xx Example Description" document - chapter "Examples > NVIC > Priority"
		for more details)
		
@Tip:
	- Open \EWARM\*.eww project file to run example on IAR
	- Open \RVMDK\*.uvproj project file to run example on Keil