MC68HC812A4 Datasheet, PDF (301/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Analog-to-Digital Converter (ATD)
Low-Power Options
ADRxH7–ADRxH0 — ATD Conversion Result Bits
These bits contain the left justified, unsigned result from the ATD
conversion. The channel from which this result was obtained depends
on the conversion mode selected. These registers are always read-only
in normal mode.
16.8 Low-Power Options
This section describes the three low-power modes:
• Run mode
• Wait mode
• Stop mode
16.8.1 Run Mode
Clearing the ATD power-up bit, ADPU, in ATD control register 2
(ATDCTL2) reduces power consumption in run mode. ATD registers are
still accessible, but the clock to the ATD is disabled and ATD analog
circuits are powered down.
16.8.2 Wait Mode
ATD operation in wait mode depends on the state of the ATD stop in wait
bit, AWAI, in ATD control register 2 (ATDCTL2).
• If AWAI is clear, the ATD operates normally when the CPU is in
wait mode
• If AWAI is set, the ATD clock is disabled and conversion continues
unless ASWAI bit in ATDCTL2 register is set.
16.8.3 Stop Mode
The ATD is inactive in stop mode for reduced power consumption. The
STOP instruction aborts any conversion sequence in progress.
Advance Information
MOTOROLA
Analog-to-Digital Converter (ATD)
MC68HC812A4 — Rev. 3.0
301