Diff: DAC/SineWave/abstract.h

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+ ******************** (C) COPYRIGHT 2010 NXPSemiconductors *******************
+ * @file    DAC\SineWave\abstract.txt 
+ * @author  NXP MCU SW Application Team
+ * @version 2.0
+ * @date    
+ * @brief   Description of the example to generate a sinewave signal by DAC.
+ ******************************************************************************
+ * 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 use DMA to generate a sinewave signal
+	Process:
+		DAC will be initialized with maximum current is 700uA. This allows a maximum update rate of 1Mhz
+		Formula for ouput voltage on AOUT is: 
+			AOUT = VALUE x ((Vrefp - Vrefn)/1024)+Vrefn
+		in which:
+		- Vrefp: tied to VDD(3.3V)
+		- Vrefn: tied to Vss
+		
+		DAC will generate a sinewave with peak to peak is within Vrefp and Vrefn. We need to prepare a
+		look up table with 60 items, each item is the value to update AOUT voltage, and it's correspondent
+		to a sample point of 1 circle sinewave signal. The formula is below:
+			for(i=0;i<NUM_SINE_SAMPLE;i++) //NUM_SINE_SAMPLE = 60
+			{
+				dac_sine_lut[i] = 512 + 512*sin(i);
+				dac_sine_lut[i] = (dac_sine_lut[i]<<6);
+			}
+		  
+		GPDMA channel 0 is configured in this example and used to transfer dac_sine_lut[i] to DAC peripheral.
+		When the last item of dac_sine_lut is transfered, GPDMA will roll back to transfer the first item.
+			
+		DAC is configured to use time out for each DAC value update and trigger GPDMA to fill DAC value register.
+		This time out value can also be used to calculate the sinewave frequency:
+			time out = (PCLK_DAC_IN_MHZ*1000000)/(SINE_FREQ_IN_HZ*NUM_SINE_SAMPLE);
+			Where:	- PCLK_DAC_IN_MHZ = 25
+					- SINE_FREQ_IN_HZ = 60
+					- NUM_SINE_SAMPLE = 60
+		
+		Observe AOUT(P0.26) signal by oscilloscope.
+					
+@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)
+	dac_sinewave_test.c: Main program
+
+@How to run:
+	Hardware configuration:		
+		This example was tested on:
+			Keil MCB1700 with LPC1768 vers.1
+				These jumpers must be configured as following:
+				- VDDIO: ON
+				- VDDREGS: ON 
+				- VBUS: 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: Configure hardware as above instruction 
+		- Step 4: Run example and observe AOUT(P0.26) signal by oscilloscope
+		
+		(Pls see "LPC17xx Example Description" document - chapter "Examples > DAC > SineWave"
+		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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