z86c96 ZiLOG Semiconductor, z86c96 Datasheet - Page 21

• Manufacturer Part Number: z86c96
• Description: Cmos Z8 Microcontroller
• Manufacturer: ZiLOG Semiconductor

Zilog
Port 1 (P17-P10). Port 1 is an 8-bit, byte programmable,
bidirectional, TTL compatible port. It has multiplexed Ad-
dress (A7-A0) and Data (D7-D0) ports. For Z86C61/62/96,
these eight I/O lines can be programmed as Input or Out-
put lines or can be configured under software control as an
address/data port for interfacing external memory. When
used as an I/O port, Port 1 may be placed under hand-
shake control. In this configuration, Port 3 line P33 and
P34 are used as the handshake controls RDY1 and
/DAV1.
DS97Z8X1600
OEN
Out
In
TTL Level Shifter
MCU
Figure 14. Port 1 Configuration
PS003501-0301
P R E L I M I N A R Y
8
R
500 K
Memory locations greater than 16,384 are referenced
through Port 1. To interface external memory, Port 1 must
be programmed for the multiplexed Address/Data mode. If
more than 256 external locations are required, Port 0 must
output the additional lines.
Port 1 can be placed in high-impedance state along with
Port 0, /AS, /DS, and R//W, allowing the microcontroller to
share common resources in multiprocessor and DMA ap-
plications. Data transfers can be controlled by assigning
P33 as a Bus Acknowledge input, and P34 as a Bus re-
quest output (Figure 14).
Port 1
(AD7-AD0)
Handshake Controls
/DAV1 and RDY1
(P33 and P34)
Auto Latch
CMOS Z8 Microcontroller
PAD
Z86C61/62/96
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