Datasheet

Analog-to-Digital Converter
ATD Registers
MC68HC912D60A — Rev. 3.1 Technical Data
Freescale Semiconductor Analog-to-Digital Converter 369
Table 18-8 lists the special channels. The last column in the table
denote the expected digital code that should be generated by the
special conversion for 8-bit resolution.
CC, CB, CA — Analog Input Channel Select Code
These bits select the analog input channel(s). Table 18-9 lists the
coding used to select the various analog input channels. In the case
of single channel scans (MULT=0), this selection code specifies the
channel for conversion. In the case of multi-channel scans (MULT=1),
this selection code represents the first channel to be examined in the
conversion sequence. Subsequent channels are determined by
incrementing the channel selection code; selection codes that reach
the maximum value wrap around to the minimum value.
Note that for special conversion mode, bits CC/CB/CA have a
different function. Instead of specifying the analog input channel, they
identify which special channel conversion is to take place. (See Table
18-8.) A summart of the channels converted and the associated result
locations for multiple channel scans can be found in Table 18-10.
Table 18-9. Analog Input Channel Select Coding
CC CB CA
Analog Input
Channel
000 AD0
001 AD1
010 AD2
011 AD3
100 AD4
101 AD5
110 AD6
111 AD7