ce100_readme.txt

一个简单实用的例程

		Readme File for Code Example:
              CE100 - ADC Sampling and IIR Filtering 
             ----------------------------------------

This file contains the following sections:
1. Code Example Description
2. Folder Contents
3. Suggested Development Resources
4. Reconfiguring the project for a different dsPIC33F device
5. Revision History


1. Code Example Description:
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In this example, ADC is configured to sample (AIN5) at 8Khz rate and coverted data is assembled as 256 sample buffer before triggering filtering operation.

Timer 3 is setup to time-out every 125 microseconds (8Khz Rate). 
As a result, the module will stop sampling and trigger a 12-bit A/D conversion on every Timer3 time-out, i.e., Ts=125us. 
At that time, the conversion process starts and completes Tc=14*Tad periods later.
When the conversion completes, the module starts sampling again. However, since Timer3 
is already on and counting, about (Ts-Tc)us later, Timer3 will expire again and trigger 
next conversion. 

ADC module clock time period is configured as Tad=Tcy*(ADCS+1)= (1/40M)*64 = 1.6us (625Khz). 
Hence the conversion time for 12-bit A/D Conversion Time Tc=14*Tad = 22.4us

void initTmr3();
Timer 3 is configured to time-out at 8Khz rate. 

void initAdc1(void);
ADC module is set-up to convert AIN5 input using CH0 S/H on Timer 3 event in 12-bit mode.

void initDma0(void);
DMA channel 0 is confiured in ping-pong mode to move the converted data from ADC to DMA RAM on every sample/convert sequence. 
It generates interrupt after every 256 sample transfer. 

void __attribute__((__interrupt__)) _DMA0Interrupt(void);
DMA interrupt service routine performs IIR filtering on the data buffer.


2. Folder Contents:
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This folder contains the following sub-folders:
a. C:\Program Files\Microchip\MPLAB C30\support\gld
        This folder will have the device GLD file, it is used for building the project. 
	This file was provided with the MPLAB