Z86C72 Datasheet, PDF (25/71 Pages) Zilog, Inc. – IR MICROCONTROLLER

Zilog
Z86C72/C92/L72/L92
IR Microcontroller
Port 2 (P27-P20). Port 2 is an 8-bit, bidirectional, CMOS shake signal assignment for Port 3, lines P31 and P36 is
compatible I/O port. These eight I/O lines can be indepen- dictated by the direction (input or output) assigned to Bit 7,
dently configured under software control as inputs or out-
puts. Port 2 is always available for I/O operation. A mask
Port 2 (Figure 13). The eight bits of Port 2 are configured
as inputs with open-drain outputs.
1
option is available to connect eight 200 kOhms (±50%)
pull-up resistors on this port. Bits programmed as outputs ^{Port 2 also has an 8-bit input OR and an AND gate which}
are globally programmed as either push-pull or open- ^{can be used to wake up the part (Figure 39). P20 can be}
drain. Port 2 may be placed under handshake control. In ^{programmed to access the edge selection circuitry (Figure}
this configuration, Port 3 lines, P31 and P36 are used as ^22).
the handshake controls lines /DAV2 and RDY2. The hand-
Z86LXX
MCU
Open-Drain
OEN
Port 2 (I/O)
Optional
Handshake Controls
/DAV2 and RDY2
(P31 and P36)
VCC
200 kΩ
Mask
Option
PAD
Out
In
Figure 13. Port 2 Configuration
DS97LVO0900
PRELIMINARY
6-25