mc68hc912d60c Freescale Semiconductor, Inc, mc68hc912d60c Datasheet - Page 368

• Manufacturer Part Number: mc68hc912d60c
• Description: Hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Analog-to-Digital Converter
Technical Data
368
MULT — Multi-Channel Sample Mode
SC — Special Channel Conversion Mode
mode is required, the existing continuous sequence must be
interrupted, the control registers modified, and a new conversion
sequence initiated.
When MULT is 0, the ATD sequence controller samples only from the
specified analog input channel for an entire conversion sequence.
The analog channel is selected by channel selection code (control
bits CC/CB/CA located in ATDCTL5).
When MULT is 1, the ATD sequence controller samples across
channels. The number of channels sampled is determined by the
sequence length value (S8C, S1C control bits). The first analog
channel examined is determined by channel selection code (CC, CB,
CA control bits); subsequent channels sampled in the sequence are
determined by incrementing the channel selection code.
SC determines if the ATD module performs A/D conversions on any
of the analog input channels (normal operation) or whether it performs
a conversion on one of the defined, special channels. The special
channels are normally used to test the A/D machine and include
converting the high and low reference potentials for the module. The
control bits CC/CB/CA are used to indicate which special channel is
to be converted.
CC
0
1
1
1
1
0 = Sample only the specified channel
1 = Sample across many channels
0 = Perform A/D conversion on an analog input channel
1 = Perform special channel A/D conversion
Table 18-8. Special Channel Conversion Select Coding
CB
X
0
0
1
1
Analog-to-Digital Converter
CA
X
0
1
0
1
(VRH + VRL)/2
reserved
reserved
Channel
Special
VRH
VRL
MC68HC912D60A — Rev. 3.1
Freescale Semiconductor
Digital Result Code
Expected
$FF
$00
$7F
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