0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
0
1
0
1
0
0
0
1
0
0
0
1
0
1
1
1
0
1
0
1
0
0
0
1
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
0
Always
±
Once
±
Hysteresis Always
±
Hysteresis Once
±
COMP0
COMP1
Initialization and Configuration
717
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Analog-to-Digital Converter (ADC)
10.3.7.3.3 High-Band Operation
To operate in the high-band region, the CIC field or the CTC field in the ADCDCCTLn register must be
programmed to 0x3. This setting causes interrupts or triggers to be generated in the high-band region
according the operation mode. An example of the state of the interrupt/trigger signal in the high-band
region for each of the allowed operational modes is shown in
. Note that a 0 in a column
following the operational mode name (Always, Once, Hysteresis Always, and Hysteresis Once) indicates
that the interrupt or trigger signal is deasserted and a 1 indicates that the signal is asserted.
Figure 10-14. High-Band Operation (CIC = 0x3 or CTC = 0x3)
10.4 Initialization and Configuration
10.4.1 Module Initialization
Initialization of the ADC module is a simple process with very few steps: enabling the clock to the ADC,
disabling the analog isolation circuit associated with all inputs that are to be used, and reconfiguring the
sample sequencer priorities (if needed).
The initialization sequence for the ADC is as follows:
1. Enable the ADC clock using the RCGCADC register (see
2. Enable the clock to the appropriate GPIO modules using the RCGCGPIO register (see
To find out which GPIO ports to enable, see the device-specific data sheet.
3. Set the GPIO AFSEL bits for the ADC input pins (see
). To determine which GPIOs to
configure, see the device-specific data sheet.
4. Configure the AINx signals to be analog inputs by clearing the corresponding DEN bit in the GPIO
Digital Enable (GPIODEN) register (see
).
5. Disable the analog isolation circuit for all ADC input pins that are to be used by writing a 1 to the
appropriate bits of the GPIOAMSEL register (see
) in the associated GPIO block.
6. If required by the application, reconfigure the sample sequencer priorities in the ADCSSPRI register.
The default configuration has Sample Sequencer 0 with the highest priority and Sample Sequencer 3
as the lowest priority.
10.4.2 Sample Sequencer Configuration
Configuration of the sample sequencers is slightly more complex than the module initialization because
each sample sequencer is completely programmable.
The configuration for each sample sequencer should be as follows:
1. Ensure that the sample sequencer is disabled by clearing the corresponding ASENn bit in the
ADCACTSS register. Programming of the sample sequencers is allowed without having them enabled.