Z380 Datasheet, PDF (2/115 Pages) Zilog, Inc. – MICROPROCESSOR

ZILOG
GENERAL DESCRIPTION (Continued)
MICROPROCESSOR
The Z380 MPU expands the basic 64 Kbyte Z80 and Z180
address space to a full 4 Gbyte (32-bit) address space.
This address space is linear and completely accessible to
the user program. The I/O address space is similarly
expanded to a full 4 Gbyte (32-bit) range and 16-bit I/O,
and both simple and block move are added.
Some features that have traditionally been handled by
external peripheral devices have been incorporated in the
design of the Z380 microprocessor. The on-chip peripher-
als reduce system chip count and reduce interconnection
on the external bus. The Z380 MPU contains a refresh
controller for DRAMs that employs a /CAS-before-/RAS
refresh cycle at a programmable rate and burst size.
Six programmable memory-chip selects are available,
along with programmable wait-state generators for each
chip-select address range.
The Z380 MPU provides flexible bus interface timing, with
separate control signals and timing for memory and
I/O. The memory bus control signals provide timing refer-
ences suitable for direct interface to DRAM, static RAM,
EPROM, or ROM. Full control of the memory bus timing is
possible because the /WAIT signal is sampled three times
during a memory transaction, allowing complete user
control of edge-to-edge timing between the reference
signals provided by the Z380 MPU. The I/O bus control
signals allow direct interface to members of the Z80 family
of peripherals, the Z8000 family of peripherals, or the
Z8500 series of peripherals. Figure 1 shows the Z380
block diagram; Figure 2 shows the pin assignments.
Note:
All signals with a preceding front slash, "/", are active Low
e.g., B//W (WORD is active Low); B/W is active Low, only)
Power connections follow conventional descriptions below:
Connection
Circuit
Device
Power
Ground
V
CC
V
DD
GND
V
SS
Clock with
Standby
Control
Chip Selects
and Waits
Refresh
Control
External Interface Logic
CPU
Data (16)
Address (32)
Interrupts
/EV
VDD
VSS
Figure 1. Z380 Functional Block Diagram
PS010001-0301