CZ80PIO

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 8 data_i data_o data_tri Features ardy astb_n 8 8 8 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 porta_i clk porta_o cdselect porta_tr portselect ce_n CZ80PIO m1_n iorq_n brdy rd_n bstb_n int_n ieo iei portb_i portb_ o 8 8 8 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 CZ80PIO Megafunction Datasheet Pin Description Name Type Description Clock clk In Sys...