Analog-to-Digital Converter (ADC)
200 October 8, 2006
Preliminary
11 Analog-to-Digital Converter (ADC)
An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a
discre te dig ital numbe r.
The Stellaris ADC module features 10-bit conversion resolution and supports two input channels,
plus an internal temperature sensor. The ADC module contains a programmable sequencer which
allows for the sampling of multiple analog input sources without controller intervention. Each
sample sequence provides flexible programming with fully configurable input source, trigger
events, interrupt generation, and sequence priority.
The Stellaris ADC provides the following features:
Two analog input channels
Single-ended and differential-input configurations
Internal temperature sensor
Sample rate of 500 thousand samples/second
Four programmable sample conversion sequences from one to eight entries long, with
corresponding conversion result FIFOs
Flexible trigger control
– Controller (software)
– Timers
– PWM
– GPIO
Hardware averaging of up to 64 samples for improved accuracy
11.1 Block Diagr am
Figure 11-1. ADC Module Block Diagram
Analog-to-Digi tal
Converter
ADCSSFIFO0
ADCSSFIFO1
ADCSSFIFO2
ADCSSFIFO3
FIFO Block
ADCSSFSTAT0
ADCSSCTL 0
ADCSSMUX0
Sample
Se quencer 0
ADCSSFSTAT1
ADCSSCTL 1
ADCSSMUX1
Sample
Se quencer 1
ADCSSFSTAT2
ADCSSCTL 2
ADCSSMUX2
Sample
Se quencer 2
ADCSSFSTAT3
ADCSSCTL 3
ADCSSMUX3
Sample
Se quencer 3
ADCUSTAT
ADCOSTAT
ADCACTSS
Control/Status
ADCSSPRI
ADCISC
ADCRIS
ADCIM
Interrupt Control
Analog Inputs
SS0 Inter rupt
SS1 Inter rupt
SS2 Inter rupt
SS3 Inter rupt
ADCEMUX
ADCPSSI
Trigg er Events
SS0
SS1
SS2
SS3
Comparator
GPIO ( PB4)
Timer
PWM
Comparator
GPIO ( PB4)
Timer
PWM
Comparator
GPIO ( PB4)
Timer
PWM
Comparator
GPIO ( PB4)
Timer
PWM