MC68HC908JK1 Datasheet, PDF (138/210 Pages) Motorola, Inc – MC68HC908JK1

Analog-to-Digital Converter (ADC)
11.3 Features
Features of the ADC module include:
• 12 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
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
ADC Status and Control ^{Read: COCO}
AIEN
ADCO
CH4
CH3
CH2
CH1
CH0
$003C
Register Write:
(ADSCR) _{Reset: 0}
0
0
1
1
1
1
1
$003D
Read: AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
ADC Data Register
(ADR)
Write:
Reset:
Indeterminate after reset
Read:
0
0
0
0
0
$003E
ADC Input Clock Register
(ADICLK)
Write:
ADIV2
ADIV1
ADIV0
Reset: 0
0
0
0
0
0
0
0
Figure 11-1. ADC I/O Register Summary
11.4 Functional Description
Twelve ADC channels are available for sampling external sources at
pins PTB0–PTB7 and PTD0–PTD3. An analog multiplexer allows the
single ADC converter to select one of the 12 ADC channels as ADC
voltage input (ADCVIN). ADCVIN is converted by the successive
approximation register-based counters. The ADC resolution is 8 bits.
When the conversion is completed, ADC puts the result in the ADC data
register and sets a flag or generates an interrupt. Figure 11-2 shows a
block diagram of the ADC.
Technical Data
138
Analog-to-Digital Converter (ADC)
MC68H(R)C908JL3 — Rev. 1.0
MOTOROLA