Datasheet

MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
152 Analog-to-Digital Converter (ADC) MOTOROLA
Analog-to-Digital Converter (ADC)
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11.3 Features
Features of the ADC module include:
• 4 channels with multiplexed input
• Linear successive approximation with monotonicity
• 8-bit resolution
• Single or continuous conversion
• Conversion complete flag or conversion complete interrupt
• Selectable ADC clock
Figure 11-1 provides a summary of the input/output (I/O) registers.
11.4 Functional Description
Four ADC channels are available for sampling external sources at pins
PTA0, PTA1, PTA4, and PTA5. An analog multiplexer allows the single
ADC converter to select one of the four ADC channels as an ADC
Addr.Register Name Bit 7654321Bit 0
$003C
ADC Status and Control
Register
(ADSCR)
See page 157.
Read: COCO
AIEN ADCO CH4 CH3 CH2 CH1 CH0
Write:
Reset:00011111
$003D Unimplemented
$003E
ADC Data Register
(ADR)
See page 159.
Read: AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0
Write:
Reset: Indeterminate after reset
$003F
ADC Input Clock Register
(ADICLK)
See page 159.
Read:
ADIV2 ADIV1 ADIV0
00000
Write:
Reset:00000000
= Unimplemented
Figure 11-1. ADC I/O Register Summary