MB90560 series
CHAPTER 16 8/10-BIT A/D CONVERTER
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Table 16.4-3 Function description of each bit of A/D control status register 0 (ADCS0)
<Check>
To rewrite the S10 bit, do so while the A/D is in a pause before conversion. If the bit is
rewritten after the conversion, the contents of ADCR become undefined.
To read the contents of the ADCR register in 10-bit mode, use a word transfer instruction
(MOVW A, 002EH, etc.).
Bit name
Function
bit15
S10: A/D conversion
resolution selection
bit
This bit selects an A/D conversion resolution.
Writing “0” to this bit selects a resolution of 10 bits, and writing “1”
to this bit selects a resolution of 8 bits.
<Caution>
The data bit to be used depends on the resolution.
bit14
bit13
ST1, ST0: Sampling
time setting bit
These bits select the sampling time for A/D conversion.
When A/D conversion is activated, analog input is fetched during
the time set in this bit.
<Caution>
Setting these bits to “00
B
” (for 8 MHz) during 16-MHz operation
may not be obtain normal fetching of the analog voltage.
bit12
bit11
CT1, CT0: Compari-
son time setting bit
These bits select the comparison time for A/D conversion.
After analog input is fetched (i.e., sampling time elapses), conver-
sion result data is defined and stored in bits 9 to 0 of this register
after the time set in these bits.
<Caution>
Setting these bits to “00
B
” (for 8 MHz) during 16-MHz operation
may not be obtain normal acquisition of the analog conversion
value.
bit10
Free bit
bit9
~
bit0
ANE2, ANE1, ANE0:
A/D conversion end
channel selection bit
The A/D conversion results are stored and the register is rewritten
each time conversion ends.
Usually, the last conversion value is stored.
The initial value of this register is undefined.
<Caution>
The conversion data protection function is provided. (See Section
16.6, "Operation of the 8/10-Bit A/D Converter.") Do not write data
to these bits during A/D conversion.