Diff: Cortex-M3/Bit-banding/abstract.h

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+ ******************** (C) COPYRIGHT 2010 NXPSemiconductors *******************
+ * @file    Cortex-M3\Bit-banding\abstract.txt 
+ * @author  NXP MCU SW Application Team
+ * @version 2.0
+ * @date    
+ * @brief   Description of the Bit-banding 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 test Bit-banding feature of Cortex-M3 processor
+	Process:
+		The processor memory map includes two bit-band regions. These occupy the lowest
+		1MB of the SRAM and peripheral memory regions respectively.
+		+ SRAM: 	Bit-band region: 	0x20000000 - 0x20100000
+					Bit-band alias:		0x22000000 - 0x23FFFFFF
+		+ PERI:		Bit-band region:	0x40000000 - 0x40100000
+					Bit-band alias:		0x42000000 - 0x43FFFFFF
+		The mapping formula:
+				bit_word_offset = (byte_offset * 32) + (bit_number * 4)
+				bit_word_address = bit_band_base + bit_word_offset
+		where:
+		+ bit_word_offset: the position of the target bit in the bit-band memory region
+		+ bit_word_addr: the address of the word in the alias memory region that maps to the target bit
+		+ bit_band_base: the starting address of the alias region
+		+ byte_offset: the number of byte in the bit-band region that contains the targeted bit
+		+ bit_number: is the bit position (0-7) of the targeted bit
+		
+		Note: In fact, the SRAM on LPC1768 just available in two ranges:
+					+ 0x2007C000 - 0x2007FFFF: for SRAM – bank 0
+					+ 0x20080000 – 0x20083FFF: for SRAM – bank 1
+			  So, just can set 'VAR_ADDR' with value that exits in two ranges SRAM above.
+		Beside, the range: 0x2009C000 - 0x2009FFF is assigned for GPIO peripheral.
+		So you can use VAR_ADDR in this range for bit-modifying GPIO registers.
+		
+		First, the program test SRAM bit-banding:
+			+ read the value at VAR_ADDRESS
+			Using bit-band access to:
+			+ read the value at 'VAR_BIT'.
+			+ clear the value at 'VAR_BIT' and print new value at VAR_ADDRESS 
+			+ re-set the value at 'VAR_BIT' and print new value at VAR_ADDRESS
+		Then, the program test PERIPHERAL bit-banding:
+		In this case, use SPCR register for testing
+			+ Assigned value SPCR: 0x00000A28
+			Use bit-band access to:
+			+ read the value at 'PERI_BIT'
+			+ clear the value at 'PERI_BIT' and print new value of SPCR 
+			+ re-set the value at 'PERI_BIT' and print new value of SPCR
+					
+@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)
+	bitband.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
+				- Remain jumpers: OFF
+			IAR LPC1768 KickStart vers.A
+				These jumpers must be configured as following:
+				- PWR_SEL: depend on power source
+				- DBG_EN : ON
+				- 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 result on serial display
+			
+		(Pls see "LPC17xx Example Description" document - chapter "Examples > Cortex-M3 > Bit-Banding"
+		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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