Precision ADC Operation
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SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Precision ADC
22.2.12 Precision ADC Calibration
The device TLV structure contains calibration values that can be used to improve the measurement
accuracy of the Precision ADC. See
of the System Controller (SYSCTL) chapter for more
details.
22.2.13 Precision ADC Interrupts
The Precision ADC has the following interrupt sources:
•
ADC14IFG0 to ADC14IFG31
The ADC14IFGx bits are set when their corresponding ADC14MEMx memory register is loaded with a
conversion result. An interrupt request is generated if the corresponding ADC14IEx bit is set and the
interrupt registers in the Arm Cortex-M4 and NVIC are configured properly. If an interrupt flag is
already set when the corresponding interrupt is enabled, then an interrupt request is generated. The
conversion result written into ADC14MEMx result register also sets the ADC14LOIFG, ADC14INIFG, or
ADC14HIIFG flag, if applicable.
•
ADC14OV: ADC14MEMx overflow
The ADC14OV condition occurs when a conversion result is written to any ADC14MEMx before its
previous conversion result was read.
•
ADC14TOV: Precision ADC conversion time overflow
The ADC14TOV condition is generated when another sample-and-conversion is requested before the
current conversion is completed. The DMA is triggered after the conversion in single-channel
conversion mode or after the completion of a sequence of channel conversions in sequence-of-
channels conversion mode.
•
ADC14LOIFG, ADC14INIFG, and ADC14HIIFG for ADC14MEMx
•
ADC14RDYIFG: Precision ADC local buffered reference ready
The ADC14RDYIFG is set when the Precision ADC local buffered reference is ready. It can be used
during extended sample mode instead of adding the maximum Precision ADC local buffered reference
settle time to the sample signal time.
22.2.13.1 ADC14IV, Interrupt Vector Generator
All Precision ADC interrupt sources are prioritized and combined to source a single interrupt vector. The
interrupt vector register ADC14IV is used to determine which enabled Precision ADC interrupt source
requested an interrupt.
The highest-priority enabled Precision ADC interrupt generates a number in the ADC14IV register (see
register description). This number can be evaluated or added to the program counter (PC) to automatically
enter the appropriate software routine. Disabled Precision ADC interrupts do not affect the ADC14IV
value.
Read access of the ADC14IV register automatically resets the highest-pending Interrupt condition and flag
except the ADC14IFGx flags. ADC14IFGx bits are reset automatically by accessing their associated
ADC14MEMx register or may be reset with software.
Write access to the ADC14IV register clears all pending Interrupt conditions and flags.
If another interrupt is pending after servicing of an interrupt, another interrupt is generated. For example, if
the ADC14OV and ADC14IFG3 interrupts are pending when the interrupt service routine accesses the
ADC14IV register, the ADC14OV interrupt condition is reset automatically. After the ADC14OV interrupt
service is completed, the ADC14IFG3 generates another interrupt.