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CHAPTER 17 8/10-BIT A/D CONVERTER
17.6 Conversion Data Protection Function of 8/10-Bit A/D
Converter
This 8/10-bit A/D converter has a conversion data protection function to enable
continuous conversion and saving of multiple data items by
μ
DMAC.
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Conversion data protection function
The 8/10-bit A/D converter has only a single conversion data register. In continuous A/D
conversion, conversion data is lost when the next conversion operation ends and its result is
stored in the register. To prevent this, the A/D converter stops A/D conversion without storing a
conversion result to the register in cases when a conversion has been completed, but the result
of the previous conversion has not been transferred yet to memory via
μ
DMAC.
The temporary stop is canceled after the conversion data has been transferred to memory by
μ
DMAC. Provided conversion data is transferred normally, A/D conversion continuously
performs without pausing.
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Caution when using the conversion data protection function
This function corresponds to the INT and INTE bits of ADCS2 register.
The conversion data protection function operates only in the interrupt enabled state (INTE = 1).
In interrupt disabled state (INTE = 0), this function does not operate. In continuous A/D
conversion, conversion results will be stored to the register in succession and older results are
lost. If
μ
DMAC is not used in the interrupt enabled state (INTE = 1), the INT bit will not be
cleared and the data protection function becomes effective, stopping the operation of the 8/10-
bit A/D converter temporarily. Clear the INT bit by the interrupt sequence in this case to cancel
the stop.
When interrupts are disabled during DMA operation while A/D conversion is temporarily
stopped, data in the conversion data registers will sometimes change before A/D conversion
starts and data is transferred. Data that was stored during the stop will be lost if data conversion
is restarted during operation stop.
Summary of Contents for MB90480 Series
Page 2: ......
Page 4: ......
Page 10: ...vi ...
Page 128: ...106 CHAPTER 4 RESET ...
Page 174: ...152 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Page 198: ...176 CHAPTER 7 MODE SETTING ...
Page 220: ...198 CHAPTER 9 TIMEBASE TIMER ...
Page 238: ...216 CHAPTER 11 WATCH TIMER ...
Page 280: ...258 CHAPTER 12 16 BIT INPUT OUTPUT TIMER ...
Page 406: ...384 CHAPTER 17 8 10 BIT A D CONVERTER ...
Page 478: ...456 CHAPTER 20 CHIP SELECTION FACILITY ...
Page 494: ...472 CHAPTER 21 ADDRESS MATCH DETECTION FUNCTION ...
Page 498: ...476 CHAPTER 22 ROM MIRROR FUNCTION SELECTION MODULE ...
Page 526: ...504 CHAPTER 23 2M 3M BIT FLASH MEMORY ...
Page 536: ...514 CHAPTER 24 EXAMPLES OF MB90F481B MB90F482B MB90F488B MB90F489B SERIAL PROGRAMMING ...
Page 570: ...548 CHAPTER 25 PWC TIMER ONLY MB90485 SERIES ...
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