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Semiconductor Group
81
On-Chip Peripheral Components
Conversion time (
t
C
):
The conversion time
t
C
includes the sample and load time. Thus,
t
C
is the total time required for one
conversion. After the load time and sample time have elapsed, the conversion itself is performed
during the rest of
t
C
. In the last machine cycle the converted result is moved to ADDAT; the busy
flag (BSY) is cleared before. The A/D converter interrupt is generated by bit IADC in register
IRCON. IADC is already set some cycles before the result is written to ADDAT. The flag IADC is
set before the result is available in ADDAT because the shortest possible interrupt latency time is
taken into account in order to ensure optimal performance. Thus, the converted result appears at
the same time in ADDAT when the first instruction of the interrupt service routine is executed.
Similar considerations apply to the timing of the flag BSY where usually a "JB BSY,$" instruction is
used for polling.
lf a continuous conversion is established, the next conversion is automatically started in the
machine cycle following the last cycle of the previous conversion.
Figure 7-32
Timing Diagram of an A/D Converter
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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 ...