MC68HC908LJ12CPB FREESCALE [Freescale Semiconductor, Inc], MC68HC908LJ12CPB Datasheet - Page 302

• Manufacturer Part Number: MC68HC908LJ12CPB
• Description: 8-bit microcontroller units
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

15.4 Functional Description
15.4.1 ADC Port I/O Pins
MC68HC908LJ12
Freescale Semiconductor
Addr.
$003C
$003D
$003E
$003F
ADC Data Register High
ADC Status and Control
ADC Data Register Low
Register Name
ADC Clock Register
—
Rev. 2.1
(ADSCR)
(ADCLK)
Register
(ADRH)
(ADRL)
The ADC provides six pins for sampling external sources at pins
PTA4/ADC0–PTA7/ADC3 and PTB6/ADC4–PTB7/ADC5. An analog
multiplexer allows the single ADC converter to select one of nine ADC
channels as ADC voltage in (V
successive approximation register-based analog-to-digital converter.
When the conversion is completed, ADC places the result in the ADC
data register, high and low byte (ADRH and ADRL), and sets a flag or
generates an interrupt.
Figure 15-2
PTA4–PTA7 and PTB6–PTB7 are general-purpose I/O pins that are
shared with the ADC channels. The channel select bits, ADCH[4:0],
define which ADC channel/port pin will be used as the input signal. The
ADC overrides the port I/O logic by forcing that pin as input to the ADC.
The remaining ADC channels/port pins are controlled by the port I/O
Reset:
Reset:
Reset:
Reset:
Read:
Read:
Read:
Read:
Write:
Write:
Write:
Write:
Figure 15-1. ADC I/O Register Summary
COCO
ADIV2
Bit 7
ADx
ADx
Analog-to-Digital Converter (ADC)
R
R
0
0
0
0
shows the structure of the ADC module.
= Unimplemented
ADIV1
AIEN
ADx
ADx
R
R
6
0
0
0
0
ADCO
ADIV0
ADx
ADx
R
R
5
0
0
0
0
ADIN
ADICLK
ADCH4
ADx
ADx
R
R
4
1
0
0
0
). V
ADIN
MODE1
ADCH3
ADx
ADx
R
R
R
3
1
0
0
0
Analog-to-Digital Converter (ADC)
is converted by the
= Reserved
MODE0
ADCH2
ADx
ADx
R
R
2
1
0
0
1
ADCH1
ADx
ADx
R
R
1
1
0
0
0
0
Technical Data
ADCH0
Bit 0
ADx
ADx
R
R
R
1
0
0
0
0
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