Z8F1601 Datasheet, PDF (153/246 Pages) Zilog, Inc. – Z8 Encore Microcontrollers with Flash Memory and 10-Bit A/D Converter

Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
Z8 Encore!^®
135
– Set CONT to 1 to select continuous conversion.
– Write to VREF to enable or disable the internal voltage reference generator.
– Set CEN to 1 to start the conversions.
3. When the first conversion in continuous operation is complete (after 5129 system
clock cycles, plus the 40 cycles for power-up, if necessary), the ADC control logic
performs the following operations:
– CEN resets to 0 to indicate the first conversion is complete. CEN remains 0 for all
subsequent conversions in continuous operation.
– An interrupt request is sent to the Interrupt Controller to indicate the first
conversion is complete. An interrupt request is not sent for subsequent
conversions in continuous operation.
4. Thereafter, the ADC writes a new 10-bit data result to {ADCD_H[7:0],
ADCD_L[7:6]} every 256 system clock cycles.
5. To disable continuous conversion, clear the CONT bit in the ADC Control register
to 0.
DMA Control of the ADC
The Direct Memory Access (DMA) Controller can control operation of the ADC includ-
ing analog input selection and conversion enable. For more information on the DMA and
configuring for ADC operations refer to the Direct Memory Access Controller chapter.
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 80. ADC Control Register (ADCCTL)
BITS
7
6
5
4
3
2
1
0
FIELD ^{CEN Reserved VREF}
CONT
ANAIN[3:0]
RESET
0
0
0
0
0000
R/W
R/W
R/W
R/W
R/W
R/W
ADDR
F70H
CEN—Conversion Enable
0 = Conversion is complete. Writing a 0 produces no effect. The ADC automatically clears
PS017610-0404
Analog-to-Digital Converter