Z86C61 Datasheet, PDF (15/46 Pages) Zilog, Inc. – CMOS Z8 MICROCONTROLLER

Port 2 (P27-P20). Port 2 is an 8-bit, bit programmable,
bidirectional, CMOS compatible port. Each of these eight
I/O lines can be independently programmed as an input
or output or globally as an open-drain output. Port 2 is
always available for I/O operation. When used as an I/O
port, Port 2 may be placed under handshake control. In this
Z86C61/62/96
Z8^® MICROCONTROLLER
configuration, Port 3 lines P31 and P36 are used as
the handshake control lines /DAV2 and RDY2. The hand-
shake signal assignment for Port 3 lines P31 and P36 is
dictated by the direction (input or output) assigned to P27
(Figure 12).
MCU
Open-Drain
OEN
Port 2 (I/O)
Handshake Controls
/DAV2 and RDY2
(P31 and P36)
PAD
Out
TTL Level Shifter
In
R ≈ 500 KΩ
Figure 12. Port 2 Configuration
Auto Latch
15