Solution
Many of the HCS12 family of 16-bit microcontrollers include support for Analog-
to-Digital conversion. The HCS12 ATD converter is modular in design. At the time of
publishing 8- channel and 16-channel implementations exist. The ATD is available on devices
with automotive, industrial and consumer temperature ranges. All of the examples in this
document are based on VDDA = 5V but the module is also used on devices that can operate at
3V. The HCS12 Analog-To-Digital converter (ATD) module is highly autonomous with an
array of flexible conversion sequences. It provides all of the timing and controls for both sample
and conversion periods for multiple conversions. Programmable conversion sequences control
at which analog source to start conversion, how many conversions to perform and whether these
should be on the same or multiple input channels. Any conversion sequence can be selected to
continuously repeat without MCU overhead. Sequences can be started by a write to a single
register or by a valid signal on an external trigger input (to synchronize the ATD conversion
process with external events). Conversions in each sequence can be configured for sample
time, resolution and result data format. The Digital-to-Analog Converter (DAC) is a unipolar,
successive-approximation converter selectable for 8- or 10-bit resolution and accurate to