TM4C129XNCZAD Datasheet, PDF (1226/2191 Pages) Texas Instruments – Tiva Microcontroller

Analog-to-Digital Converter (ADC)
Figure 18-14. High-Band Operation (CIC=0x3 and/or CTC=0x3)
COMP1
COMP0
Always – 0 0 0 0 1 1 1 0 0 1 1 0 0 0 1 1
Once – 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0
Hysteresis Always – 0 0 0 0 1 1 1 1 1 1 1 1 0 0 1 1
Hysteresis Once – 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0
18.4
18.4.1
Initialization and Configuration
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 page 414).
2. Enable the clock to the appropriate GPIO modules via the RCGCGPIO register (see page 400).
To find out which GPIO ports to enable, refer to “Signal Description” on page 1208.
3. Set the GPIO AFSEL bits for the ADC input pins (see page 806). To determine which GPIOs to
configure, see Table 31-4 on page 2067.
4. Configure the AINx signals to be analog inputs by clearing the corresponding DEN bit in the
GPIO Digital Enable (GPIODEN) register (see page 817).
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 page 822) 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.
1226
Texas Instruments-Production Data
June 18, 2014