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Semiconductor Group
74
On-Chip Peripheral Components
7.4.1
Function and Control
7.4.1.1 lnitialization and Input Channel Selection
Special function register ADCON which is illustrated in figure 7-26 is used to set the operating
modes, to check the status, and to select one of eight analog input channels.
Figure 7-26
Special Function Register ADCON (Address 0D8H)
Register ADCON contains two mode bits. Bit ADM is used to choose the single or continuous
conversion mode. In single conversion mode only one conversion is performed after starting, while
in continuous conversion mode after the first start a new conversion is automatically started on
completion of the previous one.
The busy flag BSY (ADCON.4) is automatically set when a conversion is in progress. After
completion of the conversion it is reset by hardware. This flag can be read only, a write has no
effect. There is also an interrupt request flag IADC (IRCON.0) that is set when a conversion is
completed. See section 8 for more details about the interrupt structure.
Bit
Function
MX0
MX1
MX2
Select 8 input channels of the A/D converter, see table 7-6
ADM
A/D conversion mode. When set, a continuous conversion is selected. If
ADM = 0, the converter stops after one conversion.
BSY
Busy flag. This flag indicates whether a conversion is in progress
(BSY = 1). The flag is cleared by hardware when the conversion is
completed.
These bits are not used in controlling A/D converter functions.
0DFH 0DEH 0DDH 0DCH 0DBH 0DAH 0D9H 0D8H
BD
CLK
–
BSY
ADM
MX2
MX1
MX0
0D8H
ADCON
*
Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...