AD2EVT
AD1IN[7:0]
AD1EVT
AD1IN[23:8]
ADC1
12 Bit
ADC2
12 Bit
CPU
Interface
V
CCAD
V
SSAD
AD
REFHI
AD
REFLO
Overview
692
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Analog To Digital Converter (ADC) Module
19.1 Overview
The microcontroller includes two 12-bit ADC modules. The main features of each of the ADC modules are:
•
Selectable 10-bit or 12-bit resolution, 10-bit mode is the default
•
Successive-approximation-register architecture
•
Three conversion groups – Group1, Group2 and Event Group
•
All three conversion groups can be configured to be hardware-triggered; group1 and group2 can also
be triggered by software
•
Conversion results are stored in a 64-word memory (SRAM)
–
These 64 words are divided between the three conversion groups and are configurable by software
–
Accesses to the conversion result RAM are protected by parity
•
Flexible options for generating DMA requests for transferring conversion results
•
Multichannel conversions performed in ascending order, one channel at a time
•
Single or continuous conversion modes
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Embedded self-test logic for input channel failure mode (open / short) detection
•
Embedded calibration logic for offset error correction
•
Enhanced Power-down mode
•
External event pin (ADEVT) to trigger conversions
–
ADEVT is also programmable as general-purpose I/O
•
Eight hardware events to trigger conversions
The two instances of the 12-bit ADC modules on the microcontroller share 16 analog input channels. The
connections are shown in
•
ADC1 supports 24 channels
•
ADC2 supports 16 channels, all of which are shared with ADC1
•
When using both ADC1 and ADC2 on a shared channel, the sample windows must be identical such
that the sample windows completely match each other or non-overlapping with a minimum of 2 ADC
cycles buffer between the end of one ADC’s sample window and the start of the other ADC’s sample
window.
•
The reference voltages, as well as operating supply and ground, are shared between the two ADC
cores.
Figure 19-1. Channel Assignments of Two ADC Cores