PXD20RM Datasheet, PDF (144/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

5.1.2 Device-specific implementation
PIT
PIT2
Normal trigger
PIT3
Injected trigger
System clock
/2
ACKO
ADC system
Digital
Interface
Analog
switch
ADCLKSEL
INTC
3 single-ended interrupts
EOC, Watchdog, ECH
D
A
Up to 8 extended channels
through external MUX
MUX 8
3 _{MA [2:0]}
Ch 47 (ANS15)
...
Ch 42 (ANS10)
16 channels
...
Ch 32 (ANS0)
Figure 5-1. ADC implementation
5.2 Introduction
The analog-to-digital converter (ADC) block provides accurate and fast conversions for a wide range of
applications. An ADC analog part has its corresponding digital interface (ADCDig).
The ADC digital interface contains advanced features for normal or injected conversion. An injected
conversion can be triggered by software or hardware (PIT3). A normal conversion can be triggered by
software or hardware (PIT2).
There are two types of input channels:
• Internal extended, ANS (internally multiplexed standard accuracy channels)
• External, ANX (externally multiplexed standard accuracy channels)
The mask registers present within the ADCDig can be programmed to configure which channel has to be
converted.
Three external decode signals MA[2:0] (multiplexer address) are provided for external channel selection
and are available as alternate functions on GPIO.
A conversion timing register for configuring different sampling and conversion times is associated to each
channel type.
Analog watchdogs allow continuous hardware monitoring.
PXD20 Microcontroller Reference Manual, Rev. 1
5-2
Freescale Semiconductor
Preliminary—Subject to Change Without Notice