MC68HC908JL3E Datasheet, PDF (144/226 Pages) Motorola, Inc – Microcontrollers

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
$003C
ADC Status and Control ^Read:
Register Write:
(ADSCR) _Reset:
COCO
0
$003D
Read: AD7
ADC Data Register
(ADR)
Write:
Reset:
Read:
$003E
ADC Input Clock Register
(ADICLK)
Write:
Reset:
ADIV2
0
6
AIEN
0
AD6
ADIV1
0
5
4
3
2
1
Bit 0
ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0
0
1
1
1
1
1
AD5
AD4
AD3
AD2
AD1
AD0
Indeterminate after reset
0
0
0
0
0
ADIV0
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
144
MC68H(R)C908JL3E/JK3E/JK1E — Rev. 2.0
Analog-to-Digital Converter (ADC)
MOTOROLA