Z86D99 ZILOG [Zilog, Inc.], Z86D99 Datasheet - Page 35

• Manufacturer Part Number: Z86D99
• Description: Low-Voltage Micro controllers with ADC
• Manufacturer: ZILOG [Zilog, Inc.]

PS003807-1002
Peripherals
Note:
Analog Comparators
The Z86D99/Z86L99 family includes two independent on-chip general-purpose
analog comparators as shown in Figure 13. The comparators are multiplexed with
a digital input signal by the P456CON register. They can also be used to generate
interrupts IRQ0 and IRQ2. The comparators are turned off in STOP mode.
Figure 13. Analog Comparators
Analog/Digital Converter (ADC)
The Z86D99/Z86L99 family incorporates an 8-bit ADC that uses a sigma delta
architecture (Figure 14) comprised of a modulator and a digital filter. The input is
selected (bit 3,2 from ADCCTRL) with an analog mux from 4 (P47–P44) pins that
can be configured as analog inputs (bit 7–4 from ADCCTRL).
(CREF1)
(CREF2)
(CIN1)
(CIN2)
P51
P50
P52
P53
Whenever an input pin has an analog value, the digital input
buffer has to be disabled in order to reduce the current through
the device.
P
+
–
+
–
Comparator 2
Comparator 1
R
E
L
I
M
Z86D990/Z86D991 OTP and Z86L99X ROM
P456CON
Bit4 1 = comparator
I
Low-Voltage Microcontrollers with ADC
P456CON
Bit5 1 = comparator
0 = digital
N
0 = digital
A
R
Y
IRQ2, P51 Data Latch
IRQ0, P52 Data Latch
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