gc80c510 CORERIVER Semiconductor, gc80c510 Datasheet - Page 72

• Manufacturer Part Number: gc80c510
• Description: Eprom/rom 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

6.2.7 ADC (Analog to Digital Converter)
entering at one of the twelve input channels to equivalent 10-bit digital values. The analog input level
must lie between the V
converter control register ADCON to select one of the twelve analog input pins (ADCn, n = 0–11) and
set the conversion enable and start bit, ADCON[7] and ADCON[6]. The read-write ADCON register is
located at address EFh.
This register is then updated automatically during each conversion step. The successive approximation
block performs 10-bit conversions for one input channel at a time. You can dynamically select different
channels by manipulating the analog input selection bits in ADCSEL[7:4] and ADCSELH[7:0], and the
channel selection bits in ADCSEL[3:0].
When a conversion is completed, the end-of-conversion (AD_END and ADCF) bits are automatically
set to “1”. AD_END bit is ADCON[5] and ADCF (ADCON[4]) is used for interrupt flag. Conversion result
is moved into the ADCR[7:0] and ADCON[1:0] register where it can be read. The A/D converter then
enters an idle state.
the previous result will be overwritten by the next conversion result.
Note
The 10-bit A/D converter (ADC) module uses successive approximation logic to convert analog levels
The A/D converter has the following components:
To initiate an analog-to-digital conversion procedure, you write the channel selection data in the A/D
During a normal conversion, ADC logic initially sets the successive approximation register to 000h
To run the A/D conversion, you should set the enable bit (ADCON[7]) and start bit (ADCON[6]).
Remember to read the contents of ADCR and ADCON before another conversion starts. Otherwise,
: Because the ADC does not use sample-and-hold circuitry, it is important that any fluctuations in
the analog level at the ADC0–ADC11 input pins during a conversion procedure be kept to an
absolute minimum. Any change in the input level, perhaps due to circuit noise, will invalidate the
result.
Analog comparator with successive approximation logic
D/A converter logic
ADC control register (ADCON)
Twelve multiplexed analog data input pins (ADC0–ADC11)
10-bit A/D conversion data output register (ADCR[7:0], ADCON[1:0])
DD
(or AV
REF
)
and V
SS
values.
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Functional Description