UPD17073 NEC, UPD17073 Datasheet - Page 102

• Manufacturer Part Number: UPD17073
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER WITH HARDWARE FOR DIGITAL TUNING SYSTEM
• Manufacturer: NEC

13.4 Compare Voltage Generator Block and Compare Block
reference voltage setting register to generate 16 steps of compare voltage V
the A/D converter is equal to two instruction execution times (106.6 s in normal operation mode, and 213.2 s in
the low-speed mode).
and A/D converter reference voltage setting register. Table 13-1 lists the compare voltages.
102
Figure 13-5 shows the configuration of the compare voltage generator block and compare block.
The compare voltage generator block switches over the tap decoder by using 4-bit data set to the A/D converter
In other words, this block is an R-string D/A converter.
The power source of the R string is the same as V
The compare block judges which of the voltage V
Data is compared by the comparator as soon as the ADCSTRT flag has been written to. One compare time of
By reading the content of the ADCSTRT flag, the current operating status of the comparator can be checked.
The compare result is detected by the ADCCMP flag.
Figure 13-6 shows the configuration and function of the A/D converter compare start register.
Figures 13-7 and 13-8 show the configuration and function of the A/D converter compare result detection register
1
2
R
Figure 13-5. Configuration of Compare Voltage Generator Block and Compare Block
A/D converter
reference voltage
setting register
(ADCR)
Tap decoder
0
R
1
E
R
F
V
ADCIN
1
2
V
R
REF
ADCIN
DD
that is supplied to the device.
input from a pin and compare voltage V
V
DD
Write to ADCSTRT flag
2pF
1/2 V
REF
DD
.
_
+
Comparator
PD17072,17073
REF
is greater.
ADCCMP
flag