NT68P62-01 Datasheet, PDF (14/56 Pages) List of Unclassifed Manufacturers – 8-Bit Microcontroller for Monitor (32K OTP ROM Type)

NT68P62-01
8. A/D Converters
The structure of these analog to digital converters is 6-bit
successive approximation. Analog voltage is supplied from
external sources to the A/D input pins and the result of the
conversion is stored in the 6-bit data latch registers ($0011
& $0014). The A/D channels are activated by clearing the
correspondent control bits in the ENADC control register.
When users write '0' into one of the enable control bits, its
correspondent I/O pin or DAC will be switched to the A/D
converter input pin (ADC0 & ADC1 shared with PORT10 &
PORT 11; ADC2 & ADC3 shared wit DAC0 & DAC1).
Conversion will be started by clearing CSTA bit
(CONVERSION START) in the ENADC control register.
When conversion is finished, system will set this INTADC
bit. Users can monitor this bit to get the valid A/D
conversion data in the AD latch registers ($0011 - $0014).
Users can also open interrupt sources to remind users to
get the stable digital data. Notice that only at the activated
A/D channel, its latched data are available.
The analog voltage to be measured should be stabled
during the conversion operation and the variation will not
exceed LSB for the best accuracy in measurement.
Addr. Register INIT
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
R/W
$0010
ENADC
FFH _CSTA
-
-
-
ENADC3 ENADC2
ENADC1 ENADC0
W
$0011 AD0 REG C0H
-
-
AD05 AD04
AD03
AD02
AD01
AD00
R
$0012 AD1 REG 00H
-
-
AD15 AD14
AD13
AD12
AD11
AD10
R
$0013 AD2 REG 00H
-
-
AD25 AD24
AD23
AD22
AD21
AD20
R
$0014 AD3 REG 00H
-
-
AD35 AD34
AD33
AD32
AD31
AD30
R
$001B
IEIRQ2
00H
-
-
-
-
INTADC
INTV
INTE1
INTMR R/W
$001E
IRQ2
00H
-
-
-
-
INTADC
INTV
INTE1
INTMR
R
-
-
-
-
CLRADC CLRV
CLRE1
CLRMR
W
Reference ADC Table (V_DD = 5.0V)
15
1.50V
1C
2.06V
23
2.59V
2A
3.14V
16
1.58V
1D
2.12V
24
2.67V
2B
3.22V
17
1.66V
1E
2.20V
25
2.75V
2C
3.30V
18
1.74V
1F
2.28V
26
2.82V
2D
3.38V
19
1.82V
20
2.35V
27
2.91V
2E
3.46V
1A
1.90V
21
2.44V
28
2.98V
2F
3.54V
1B
1.98V
22
2.51V
29
3.07V
30
3.62V
Note: It is strongly recommended that the ADC’s input signal should be allocated in the ADC’s linear voltage range
(1.5V~3.5V) to obtain a stable digital value. Do not use the outer ranges (0V~1.4V & 3.6V~5.0V) in which the
converted digital value is not guaranteed.
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