ce010_readme.txt

休眠模式下的AD转换

                              Readme File for Code Example:
            CE010 - Performing A/D conversions in SLEEP (low-power) mode
            -------------------------------------------------------------

This file contains the following sections:
1. Code Example Description
2. Folder Contents
3. Suggested Development Resources
4. Reconfiguring the project for a different dsPIC30F device
5. Revision History

1. Description:
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Microchip's 16-bit dsPIC Digital Signal Controllers feature one or more on-chip A/D converters. These 10 or 12-bit A/D converter modules are capable of performing Analog to Digital conversions even when the device has been placed in a low-power mode of operation, for example SLEEP or IDLE mode.

When a device is placed in SLEEP mode, the CPU turns off the system clock thereby ensuring the device consumes the lowest power. The absence of the system clock signal minimizes digital noise. Applications may therefore find it beneficial to perform A/D conversions when the device is placed in SLEEP mode. To allow the A/D converter to operate when the device is in SLEEP mode, the A/D converter on dsPIC DSC devices feature an internal RC oscillator that can provide clock signals to the A/D converter module alone. This RC oscillator is enabled by setting the ADRC bit in the ADCON3 control register. When the A/D converter uses the ADRC oscillator for a clock source, the conversion rate is not user-configurable. Refer to the device datasheets for the conversion rate of the ADRC oscillator.

Note: The ADRC oscillator is a different oscillator than the on-chip 7.37 MHz Fast RC oscillator and the 512 KHz Low-power RC oscillator.

The Code Example attached here demonstrates how the user may enable the ADRC oscillator and perform A/D conversions in SLEEP mode. An A/D interrupt will wake the processor up from SLEEP mode. Upon waking up, the processor will vector to the A/D interrupt service routine (ISR) if one has been defined and enabled. If an A/D ISR has not been enabled, the processor will execute the instruction immediately following the PWRSAV instruction that placed the device in SLEEP mode.

2. Folder Contents:
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This folder contains the following sub-folders:
a. gld
        This folder contains a linker script file for the example project.
        This file is used for building the project for a 30F6014A device.
        This file simply includes the relevant device linker script, 
        "p30F6014A.gld" and the relevant MPLAB