Z5380 Datasheet, PDF (1/37 Pages) Zilog, Inc. – SMALL COMPUTER SYSTEM INTERFACE (SCSI)

ZILOG
Z5380 SCSI
PRODUCT SPECIFICATION
FEATURES
Z5380 SCSI
SMALL COMPUTER
SYSTEM INTERFACE (SCSI)
s Pin Compatible with the Industry Standard 5380
s Supports Target and Initiator Roles
s 40-Pin DIP or 44-Pin PLCC Package Styles
s Arbitration Support
s Low-Power CMOS
s DMA or Programmed I/O Data Transfers
s Asynchronous Interface (Supports 1.5 MB/s)
s Supports Normal or Block Mode DMA
s Direct SCSI Bus Interface with On-Board 48 mA Drivers s Memory or I/O Mapped CPU Interface
GENERAL DESCRIPTION
The Z5380 SCSI (Small Computer System Interface) con-
troller is designed to implement the SCSI protocol as
defined by the ANSI X3.131-1986 standard, and is fully
compatible with the industry standard 5380. It is capable
of operating both as a Target and as an Initiator. Special
high-current open-drain outputs enable the Z5380 to di-
rectly interface to, and drive, the SCSI bus. The Z5380 has
the necessary interface hook-ups which allows the system
CPU to communicate with it like any other peripheral
device. The CPU can read from, or write to, the SCSI
registers which are addressed as standard or memory-
mapped I/Os (Figure 1).
The Z5380 increases the system performance by minimiz-
ing the CPU intervention in DMA operations which the SCSI
controls. The CPU is interrupted by the SCSI when it
detects a bus condition that requires attention. It also
supports arbitration and reselection. The Z5380 has the
proper hand-shake signals to support normal and block
mode DMA operations with most DMA controllers avail-
able (Figure 2).
Notes:
All Signals with a preceding front slash, "/", are active Low, e.g.,
B//W (WORD is active Low); /B/W (BYTE is active Low, only).
Power connections follow conventional descriptions below:
Connection
Circuit
Device
Power
V_CC
V_DD
Ground
GND
V_SS
PS97SCC0100
PS009101-0201
1