Datasheet

Analog-to-Digital Converter (ADC)
Interrupts
MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
MOTOROLA Analog-to-Digital Converter (ADC) 155
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11.4.4 Continuous Conversion
In the continuous conversion mode, the ADC continuously converts the
selected channel filling the ADC data register (ADR) with new data after
each conversion. Data from the previous conversion will be overwritten
whether that data has been read or not. Conversions will continue until
the ADCO bit is cleared. The COCO bit (ADSCR, $003C) is set after
each conversion and can be cleared by writing the ADC status and
control register or reading of the ADC data register.
11.4.5 Accuracy and Precision
The conversion process is monotonic and has no missing codes.
11.5 Interrupts
When the AIEN bit is set, the ADC module is capable of generating a
central processor unit (CPU) interrupt after each ADC conversion. A
CPU interrupt is generated if the COCO bit is at logic 0. The COCO bit
is not used as a conversion complete flag when interrupts are enabled.
11.6 Low-Power Modes
The following subsections describe the ADC in low-power modes.
11.6.1 Wait Mode
The ADC continues normal operation during wait mode. Any enabled
CPU interrupt request from the ADC can bring the microcontroller unit
(MCU) out of wait mode. If the ADC is not required to bring the MCU out
of wait mode, power down the ADC by setting the CH[4:0] bits in ADSCR
to logic 1’s before executing the WAIT instruction.