Z86E61 Zilog., Z86E61 Datasheet - Page 10

• Manufacturer Part Number: Z86E61
• Description: CMOS Z8 16K/32K EPROM MICROCONTROLLER
• Manufacturer: Zilog.

PIN FUNCTIONS (Continued)
Port 2 (P27-P20). Port 2 is an 8-bit, bit programmable, bi-
directional, 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 can be placed under handshake control. In this
10
Open-Drain
OEN
Out
In
TTL Level Shifter
Z86E61
MCU
/E63
Figure 8. Port 2 Configuration
P R E L I M I N A R Y
R
500 k
configuration, Port 3 lines P31 and P36 are used as the
handshake control lines /DAV2 and RDY2. The handshake
signal assignment for Port 3 lines, P31 and P36, is dictated
by the direction (input or output) assigned to P27
(Figure 8 and Table 5).
Port 2 (I/O)
Handshake Controls
/DAV2 and RDY2
(P31 and P36)
Auto Latch
PAD
WITH
Z86E61/E63 Z8
16K/32K EPROM
®
MCU