Z8F1680SH020SG Datasheet, PDF (214/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
189
the V_REF pin. When RBUF is disabled, the ADC must have the reference voltage supplied
externally through the V_REF pin. RBUF is controlled by the REFEN bit in the ADC Control
Register.
14.2.4. Internal Voltage Reference Generator
The Internal Voltage Reference Generator provides the voltage, VR2, for the RBUF. VR2
is 1.6 V.
14.2.5. Calibration and Compensation
You can calibrate and store the values into Flash, or the user code can perform a manual
offset calibration. There is no provision for manual gain calibration.
14.3. ADC Control Register Definitions
The registers that control analog-to-digital conversion functions are defined in this sec-
tion.
14.3.1. ADC Control Register 0
The ADC Control Register 0, shown in Table 101, initiates the A/D conversion and
provides ADC status information.
Table 101. ADC Control Register 0 (ADCCTL0)
Bits
7
6
5
4
3
2
1
0
Field
START INTREF_SEL REFEN ADCEN
ANAIN[3:0]
Reset
0
0
0
0
0
0
0
0
R/W
R/W1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Address
F70h
Bit Position
[7]
START
[6]
INTREF_SEL
Value
(H) Description

ADC Start/Busy
0
Writing a 0 has no effect.
Reading a 0 indicates the ADC is available to begin a conversion.
1
Writing a 1 starts a conversion.
Reading a 1 indicates that a conversion is currently in progress.
0
Select 1.6 V as internal reference.
1
Select AVDD as internal reference.
PS025015-1212
PRELIMINARY
Analog-to-Digital Converter