Z86L825 Datasheet, PDF (23/79 Pages) Zilog, Inc. – 20-Pin Low-Voltage IR Microcontrollers

Z86L825/826/827
20-Pin Low-Voltage IR Microcontrollers
16
Port 3 (P36–P31)
Port 3 (see Figure 8) is a 5-bit, CMOS-compatible port consisting of three fixed
inputs (P33–P31) and two fixed outputs (P36 and P34). Port 3 can be configured
under software control for interrupt and output from the counter/timers. P31, P32,
and P33 are standard CMOS inputs; P34 and P36 are push-pull outputs.
Z86L82X
MCU
P31
P32
P33
Port 3 (I/O)
P34
P36
P31 (AN1)
Pref
R247 = P3M
D1
1 = Analog
0 = Digital
DIG.
Comp1
+
AN.
–
IRQ2, P31 Data Latch
P32 (AN2)
P33 (Ref2)
Comp1
+
–
IRQ0, P32 Data Latch
From Stop Mode
Recovery Source of SMR
IRQ1, P33 Data Latch
Figure 8. Port 3 Configuration
One on-board comparator processes analog signals on P32 with reference to
the voltage on P33. The analog function is enabled by programming the Port 3
Mode Register (bit 1). P31 and P32 are programmable as rising, falling, or both
PS008808-1203
PRELIMINARY