Z86L78 Datasheet, PDF (15/59 Pages) Zilog, Inc. – IR/Low-Voltage Microcontroller

Zilog
Z86L78
IR/Low-Voltage Microcontroller
Port 2 (P27-P20). Port 2 is an 8-bit, bidirectional, CMOS- The Z86L78 wakes up with the eight bits of Port 2 config-
compatible I/O port. These eight I/O lines can be indepen- ured as inputs with open-drain outputs.
dently configured under software control as inputs or out-
puts. Port 2 is always available for I/O operation. A mask
Port 2 also has an 8-bit input OR and an AND gate which
1
option is available to connect eight 200 KOhm (±50%) pull- ^{can be used to wake up the part (Figure 33). P20 can be}
up resistors on this port. Bits programmed as outputs are ^{programmed to access the edge selection circuitry (Figure}
globally programmed as either push-pull or open-drain. ^10).
Z86L78
MCU
Port 2 (I/O)
Open-Drain
OEN
Out
In
VCC
200 kΩ
Mask
Option
Pad
Figure 10. Port 2 Configuration
DS97LVO0701
2-15