M16C/62P Group (M16C/62P, M16C/62PT)
18. A/D Converter
Rev.2.41
Jan 10, 2006
Page 236 of 390
REJ09B0185-0241
Figure 18.3
ADCON2 Register
A/D Control Register 2
(1)
Symbol
ADCON2
Bit Symbol
RW
NOTES :
1.
2.
3.
CKS0
0
1
0
1
0
1
0
1
1
1
A/D Input Group Select Bit
b2 b1
0 0 : Port P10 group is selected
0 1 : Do not set
1 0 : Port P0 group is selected
(2)
1 1 : Port P2 group is selected
If VCC2 < VCC1, do not use AN0_0 to AN0_7 and AN2_0 to AN2_7 as analog input pins.
Frequency Select Bit 2
(3)
0
1
—
(b7-b5)
—
03D4h
1
1
Divide-by-3 of fAD
fAD
1
0
1
1
0
Reserved Bit
Nothing is assigned.
When w rite, set to “0”. When read, their contents are “0”.
0
After Reset
00h
CKS1
The ØAD frequency must be 12 MHz or less. The selected ØAD frequency is determined by a combination of the CKS0
bit in the ADCON0 register, the CKS1 bit in the ADCON1 register, and the CKS2 bit in the ADCON2 register.
Set to “0”
0: Selects fAD, fAD divided by 2, or fAD
divided by 4.
1: Selects fAD divided by 3, fAD divided
by 6, or fAD divided by 12.
Address
Bit Name
Function
0 : Without sample and hold
1 : With sample and hold
A/D Conversion Method Select
Bit
Divide-by-6 of fAD
Divide-by-4 of fAD
Divide-by-2 of fAD
ØAD
Ddivide-by-12 of fAD
0
0
0
If the ADCON2 register is rew ritten during A/D conversion, the conversion result w ill be indeterminate.
CKS2
0
RW
CKS2
RW
RW
ADGSEL0
RW
ADGSEL1
RW
SMP
—
(b3)
0
b7 b6 b5 b4 b3 b2 b1 b0
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