mc68hc908qf4 Freescale Semiconductor, Inc, mc68hc908qf4 Datasheet - Page 42

• Manufacturer Part Number: mc68hc908qf4
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Analog-to-Digital Converter (ADC)
3.7.1 ADC Status and Control Register
Data Sheet
42
NOTE:
The following paragraphs describe the function of the ADC status and control
register (ADSCR). When a conversion is in process and the ADSCR is written, the
current conversion data should be discarded to prevent an incorrect reading.
COCO — Conversions Complete Bit
The write function of the COCO bit is reserved. When writing to the ADSCR
register, always have a 0 in the COCO bit position.
AIEN — ADC Interrupt Enable Bit
ADCO — ADC Continuous Conversion Bit
CH[4:0] — ADC Channel Select Bits
Address: $003C
Reset:
Read:
Write:
In non-interrupt mode (AIEN = 0), COCO is a read-only bit that is set at the end
of each conversion. COCO will stay set until cleared by a read of the ADC data
register. Reset clears this bit.
In interrupt mode (AIEN = 1), COCO is a read-only bit that is not set at the end
of a conversion. It always reads as a 0.
When this bit is set, an interrupt is generated at the end of an ADC conversion.
The interrupt signal is cleared when ADR is read or ADSCR is written. Reset
clears the AIEN bit.
When set, the ADC will convert samples continuously and update ADR at the
end of each conversion. Only one conversion is allowed when this bit is cleared.
Reset clears the ADCO bit.
CH4, CH3, CH2, CH1, and CH0 form a 5-bit field which is used to select one of
the four ADC channels. The five select bits are detailed in
1 = Conversion completed (AIEN = 0)
0 = Conversion not completed (AIEN = 0) or CPU interrupt enabled
1 = ADC interrupt enabled
0 = ADC interrupt disabled
1 = Continuous ADC conversion
0 = One ADC conversion
Freescale Semiconductor, Inc.
COCO
Figure 3-4. ADC Status and Control Register (ADSCR)
For More Information On This Product,
Bit 7
(AIEN = 1)
0
Analog-to-Digital Converter (ADC)
= Unimplemented
Go to: www.freescale.com
AIEN
6
0
ADCO
5
0
CH4
4
1
CH3
3
1
CH2
2
1
MC68HC908QF4 — Rev. 1.0
Table
CH1
1
1
3-1. Care
MOTOROLA
Bit 0
CH0
1