CZ80PIO Datasheet, PDF (1/4 Pages) List of Unclassifed Manufacturers – Hereinafter Referred to As PIO, is a Dual-Port Device

CZ80PIO
Peripheral Device
Megafunction
General Description
The CZ80PIO, hereinafter referred to as PIO, is a dual-port device which can be programmed by the system
software to function as a broad range of peripheral devices that are compatible with the Z80CPU such as most
keyboards, printers etc.
System design is simplified because the PIO connects directly to the Z80CPU with no additional logic. In larger
systems, address decoders and buffers may be required.
The CZ80PIO is a microcode-free design developed for reuse in ASIC and FPGA implementations. The design
is strictly synchronous, with no internal tri-states and a synchronous reset.
Symbol
8 _{data_i}
8 data_o
ardy
astb_n
data_tri
clk
cdselect
portselect
porta_i ⁸
porta_o 8
porta_tr 8
ce_n _CZ80PIO
m1_n
iorq_n
rd_n
brdy
bstb_n
int_n
ieo
iei
portb_i ₈
portb_ 8
o8
Features
• ^{Provides a direct interface between Z80}
microprocessor systems and peripheral
devices
• ^{Two ports with interrupt-driven handshake for}
fast response
• ^{Four programmable operating modes:}
• Output Mode (both ports)
• Input Mode (both ports)
• Bi-directional (Port A only)
• Bit Control Mode (both ports)
• ^{Programmable interrupts on peripheral status}
conditions
Applications
• ^{Programmable, dual - port device}
• ^{Interface for a wide range of peripheral}
devices such as:
• Keyboards
• Printers
• Paper table readers
• PROM programmers etc.
CAST, Inc.
May 2004
Page 1