Fujitsu MB91260B Series Hardware Manual page 352

Table 14.4-3 Function of Each Bit in A/D Control Status Register (ADCS) (1 / 2)
Bit Name
BUSY:
bit15
A/D converting bit
INT:
bit14
Interrupt request
flag bit
INTE:
bit13 Interrupt request
enable bit
PAUS:
bit12
Halt flag bit
S10:
Analog to digital
bit11 conversion
resolution selection
bit
bit10 Unused bit
• Operational display bit of A/D converter
• When reading, if this bit is "0", it indicates that A/D conversion is stopped. If it is "1",
it indicates that A/D conversion is ongoing.
• When writing, writing "0" to this bit forcibly stops A/D conversion. When "1" is
written, the conversion is not changed and no others are affected.
• "1" is always read during read-modify-write.
Note:
Do not perform a forced stop and software activation (BUSY = 0, START = 1) at the
same time.
• This bit is set to "1" if data is set in the A/D data register through A/D conversion.
• If this bit and the interrupt request enable bit (ADCS: INTE) are "1", an interrupt
request is generated.
• When writing, a "0" clears this bit, and with "1" no change is made, and there are no
other effects.
• "1" is always read during read-modify-write.
Note:
Clear this bit by writing "0" to it when A/D is stopped.
• This bit is used to enable and disable the interrupt output to CPU.
• If this bit and the interrupt request flag bit (ADCS: INT) are "1", an interrupt request
is generated.
• It is set to "1" when A/D conversion is suspended.
This A/D converter has only one A/D data register. For this reason, when in continuous
conversion mode, if the old conversion results are not completely read via the CPU,
they will be overwritten by the next conversion results and lost. Consequently, when
using continuous conversion mode, as a rule you should perform settings so that
conversion results are sent to memory each time conversion is completed. However,
such case can be assumed that the conversion data transfer is not completed before the
next conversion in the multiple interrupts, etc. The function of this bit was created in
consideration of this case. After conversion is completed, set this bit to "1" while
sending the contents of the data register. During this time, A/D conversion will halt
and will not store the next conversion data.
• "1" is always read during read-modify-write.
• This bit is used to select the A/D conversion resolution.
• Write "0" to this bit to select 10-bit resolution. Write "1" to this bit to select 8-bit
resolution.
Notes:
• The data bit used are different depending on the resolution.
• Only rewrite this bit before conversion begins, with the A/D operation stopped.
• The read value is indeterminate.
• Writing to this bit has no effect to operation.
CHAPTER 14 8/10-BIT A/D CONVERTER
Function
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