Z8F082ASJ020EG Datasheet, PDF (151/282 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F082A Series
Product Specification
134
ADC Control Register 0
The ADC Control Register 0 (ADCCTL0) selects the analog input channel and initiates
the analog-to-digital conversion. It also selects the voltage reference configuration.
Table 73. ADC Control Register 0 (ADCCTL0)
Bit
7
6
5
4
3
2
1
0
Field
CEN REFSELL REFOUT CONT
ANAIN[3:0]
RESET
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Address
F70H
Bit
Description
[7]
CEN
Conversion Enable
0 = Conversion is complete. Writing a 0 produces no effect. The ADC automatically clears
this bit to 0 when a conversion is complete.
1 = Begin conversion. Writing a 1 to this bit starts a conversion. If a conversion is already in
progress, the conversion restarts. This bit remains 1 until the conversion is complete.
[6]
REFSELL
Voltage Reference Level Select Low Bit
In conjunction with the High bit (REFSELH) in ADC Control/Status Register 1, this deter-
mines the level of the internal voltage reference; the following details the effects of {REF-
SELH, REFSELL}; note that this reference is independent of the Comparator reference.
00 = Internal Reference Disabled, reference comes from external pin.
01 = Internal Reference set to 1.0 V.
10 = Internal Reference set to 2.0 V (default).
11 = Reserved.
[5]
REFOUT
Internal Reference Output Enable
0 = Reference buffer is disabled; Vref pin is available for GPIO or analog functions.
1 = The internal ADC reference is buffered and driven out to the V_REF pin.
Caution: When the ADC is used with an external reference ({REFSELH,REFSELL}=00),
the REFOUT bit must be set to 0.
[4]
CONT
Conversion
0 = Single-shot conversion. ADC data is output once at completion of the 5129 system clock
cycles (measurements of the internal temperature sensor take twice as long).
1 = Continuous conversion. ADC data updated every 256 system clock cycles after an initial
5129 clock conversion (measurements of the internal temperature sensor take twice as
long).
[3:0]
ANAIN[3:0]
Analog Input Select
These bits select the analog input for conversion. Not all Port pins in this list are available in
all packages for the Z8 Encore! XP F082A Series. For information about port pins available
with each package style, see the Pin Description chapter on page 8. Do not enable unavail-
able analog inputs. Usage of these bits changes depending on the buffer mode selected in
ADC Control/Status Register 1.
PS022827-1212
PRELIMINARY
ADC Control Register Definitions