ANALOG-TO-DIGITAL CONVERTER
M68HC16 Z SERIES
8-2
USER’S MANUAL
Figure 8-1 ADC Block Diagram
8.2.1 Analog Input Pins
Each of the eight analog input pins (AN[7:0]) is connected to a multiplexer in the ADC.
The multiplexer selects an analog input for conversion to digital data.
Analog input pins can also be read as digital inputs, provided the applied voltage
meets V
IH
and V
IL
specifications. When used as digital inputs, the pins are organized
into an 8-bit port (PORTADA), and referred to as PADA[7:0]. There is no data direction
register because port pins are input only.
16 ADC BLOCK 2
RESULT 7
RESULT 6
RESULT 5
RESULT 4
RESULT 3
RESULT 2
RESULT 1
RESULT 0
SAR
RC DAC ARRAY
AND
COMPARATOR
ANALOG
MUX
AND SAMPLE
BUFFER AMP
CLK SELECT/
PRESCALE
AN7/PADA7
AN6/PADA6
AN5/PADA5
AN4/PADA4
AN3/PADA3
AN2/PADA2
AN1/PADA1
AN0/PADA0
VRH
VRL REFERENCE
VDDA
VSSA SUPPLY
ADC BUS
INTERFACE UNIT
INTERMODULE BUS (IMB)
RESERVED
RESERVED
RESERVED
RESERVED
VRH
VRL
(VRH–VRL)/2
RESERVED
MODE
AND
TIMING
CONTROL
INTERNAL
CONNECTIONS
PORT ADA DATA
REGISTER
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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