Z8F6421PM020SC Datasheet, PDF (195/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
175
ADC Control Register Definitions
ADC Control Register
The ADC Control register selects the analog input channel and initiates the analog-to-dig-
ital conversion.
Table 85. ADC Control Register (ADCCTL)
BITS
7
6
5
4
3
2
1
0
FIELD ^CEN
Reserved VREF
CONT
ANAIN[3:0]
RESET
0
1
0
R/W
ADDR
R/W
F70H
CEN—Conversion Enable
0 = Conversion is complete. Writing a 0 produces no effect. The ADC automatically clears
this bit to 0 when a conversion has been completed.
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.
Reserved—Must be 0.
VREF
0 = Internal voltage reference generator enabled. The VREF pin should be left uncon-
nected (or capacitively coupled to analog ground) if the internal voltage reference is
selected as the ADC reference voltage.
1 = Internal voltage reference generator disabled. An external voltage reference must be
provided through 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—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 Z8F642x familyZ8R642x family of products. Refer to the Signal
and Pin Descriptions chapter for information regarding the Port pins available with each
package style. Do not enable unavailable analog inputs.
0000 = ANA0
0001 = ANA1
0010 = ANA2
0011 = ANA3
PS019915-1005
Analog-to-Digital Converter