Z8 Encore! XP® F08xA Series
Product Specification
117
ADC Control Register Definitions
ADC Control Register 0
The ADC Control register selects the analog input channel and initiates the analog-to-dig-
ital conversion.
Table 70. ADC Control Register 0 (ADCCTL0)
7
6
5
4
CONT
0
3
2
1
0
BITS
CEN
0
REFSELL REFEXT
ANAIN[3:0]
FIELD
RESET
R/W
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
F70H
ADDR
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.
REFSELL—Voltage Reference Level Select Low Bit; in conjunction with the High bit
(REFSELH) in ADC Control/Status Register 1, this determines the level of the internal volt-
age reference; the following details the effects of {REFSELH, 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
REFEXT - External Reference Select
0 = External reference buffer is disabled; Vref pin is available for GPIO functions
1 = The internal ADC reference is buffered and connected to the Vref pin
CONT
0 = Single-shot conversion. ADC data is output once at completion of the 5129 system
clock cycles
1 = Continuous conversion. ADC data updated every 256 system clock cycles
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® F08xA Series. Refer to the chapter “Pin Descrip-
tion” on page 7 for information regarding the Port pins available with each package style.
Do not enable unavailable analog inputs. Usage of these bits changes depending on the
buffer mode selected in ADC Control/Status Register 1.
PS024705-0405
P R E L I M I N A R Y
Analog-to-Digital Converter
ZILOG [ ZILOG, INC. ]
