1.5.24 1.29.22 Sigma-Delta Analog Digital Converter (SDADC)
The Sigma-Delta Analog-to-Digital Converter (SDADC) converts analog signals to digital values. This peripheral provides below features:
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16bit resolution
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Up to 1,500,000 divided by Over Sampling Ratio (OSR) samples per second
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Three analog differential inputs
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Conversion Range:
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Differential mode: VREF to +VREF
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Singleended mode: 0V to +VREF
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Signed results
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Eventtriggered conversion (one event input)
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Optional DMA transfer of conversion settings or result
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Single, continuous and sequencing options
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Hardware gain, offset and shift compensation
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Windowing monitor
Using The Library
SDADC converts enabled channel on software or hardware triggers. It provides both polling and callback methods to indicate the end of conversion to read the converted data from the result register.
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With polling, the application will need to continuously poll to check if the conversion is completed.
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With callback, the registered callback function will be called once the conversion is completed. This means the application do not have to poll continuously.
Callback method
This example demonstrates how to read conversion result in the callback function. One channel is enabled and configured to start conversion on hardware trigger.
int16_t result; /* This function is called after conversion of last channel in the user sequence */ void SDADC_EventHandler(SDADC_STATUS status, uintptr_t context) { result = SDADC_ConversionResultGet(); } int main(void) { /* Register callback function for SDADC end of conversion interrupt*/ SDADC_CallbackRegister(SDADC_EventHandler, (uintptr_t)NULL); while(true) { } }
Polling method
This example demonstrates how to start conversion and read the converted data in polled mode. One channel is enabled and configured to start conversion on software trigger.
/* Start conversion */ SDADC_ConversionStart(); /* Wait till ADC conversion result is available */ while(!SDADC_ConversionResultIsReady(CH0)) { }; /* Read the ADC result */ result = SDADC_ConversionResultGet();
Library Interface
Sigma-Delta Analog Digital Converter peripheral library provides the following interfaces:
Functions
Name | Description |
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SDADC_Initialize | Initializes given instance of SDADC peripheral |
SDADC_Enable | Enables the SDADC module |
SDADC_Disable | Disables the SDADC module |
SDADC_ConversionStart | Starts the SDADC conversion with the software trigger |
SDADC_ConversionResultIsReady | Returns the status of the conversion |
SDADC_ConversionResultGet | Returns the conversion result |
SDADC_ConversionSequenceIsFinished | Returns the status of automatic sequence conversion |
SDADC_WindowMonitorIsSet | Returns the status of the window monitor |
SDADC_ComparisonWindowSet | Returns the status of automatic sequence conversion |
SDADC_CallbackRegister | Registers the function to be called from interrupt |
Data types and constants
Name | Type | Description |
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SDADC_CALLBACK_OBJECT | Struct | Callback structure |
SDADC_STATUS | Enum | Identifies interrupt status flags |
SDADC_CALLBACK | Typedef | Defines the function pointer data type and function signature for the SDADC peripheral callback function |