Diff: Cortex-M3/Privilege_mode/abstract.h

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+ ******************** (C) COPYRIGHT 2010 NXPSemiconductors *******************
+ * @file    Cortex-M3\Privilege_mode\abstract.txt 
+ * @author  NXP MCU SW Application Team
+ * @version 2.0
+ * @date    
+ * @brief   Description of the Privilege mode 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 change privilege to unprivilege mode and vice vesa.
+	Process:
+		CONTROL[0] register controls the privilege level for software execution when the 
+		processor is in Thread mode. So, we can access to get/set CONTROL[0] to change Thread
+		mode privilege level.
+		
+		Out of reset, Thread mode is privilege.
+		Read CONTROL[0] to check if it is truly privilege or not.
+		If Thread mode is not privilege, so it's not compliant with Cortex-M3 Technical, the 
+		program will enter into infinite error loop.
+		Then, set CONTROL[0] = 1, changing Thread mode to unprivilege.
+		Re-check by re-read CONTROL[0] again.
+		A system service will be call __SCV(). In this exception mode, we can switch back Thread 
+		mode into privilege 
+		(Note that:
+			When Thread mode has been changed from privilege to use, it cannot change ifself back 
+			to privilege. Only a handler can change the privilege of Thread mode.
+			Handler mode is always privilege.
+		)
+		After call handler, get CONTROL[0] to check if it is truly privilege or not.
+		If not, program will enter to error loop.
+		
+		We use two LED to display status of Thread mode.
+		LED1: turn on if Thread mode is privilege.
+		LED2: turn on if Thread mode is unprivilege.
+		- Using MCB1700 board: LED1 is P1.28, LED2 is P1.29
+		- Using IAR1700 board: LED1 is P1.25, LED2 is P0.4
+					
+@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)
+	priviledge.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
+				- LED: ON
+				- Remain jumpers: OFF
+			IAR LPC1768 KickStart vers.A
+				These jumpers must be configured as following:
+				- PWR_SEL: depend on power source
+				- DBG_EN : ON
+				- ACC_IRQ/LED2: 2-3 (LED2)
+				- Remain jumpers: OFF
+				
+		Serial display configuration:(e.g: TeraTerm, Hyperterminal, Flash Magic...) 
+			– 115200bps 
+			– 8 data bit 
+			– No parity 
+			– 1 stop bit 
+			– No flow control 
+	
+	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: Connect UART0 on this board to COM port on your computer
+		- Step 4: Configure hardware and serial display as above instruction 
+		- Step 5: Run example and observe on serial display
+					+ Press '1' to change into unprivilege mode
+					+ Press '2' to switch back to privilege mode
+			
+		(Pls see "LPC17xx Example Description" document - chapter "Examples > Cortex-M3 > Privilege_mode"
+		for more details)
+		
+@Tip:
+	- Open \EWARM\*.eww project file to run example on IAR
+	- Open \RVMDK\*.uvproj project file to run example on Keil
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