Z85233 Datasheet, PDF (160/317 Pages) Zilog, Inc. – The Zilog SCC Serial Communication Controller

APPLICATION NOTE
7
THE Z180^™ INTERFACED
WITH THE SCC AT MHZ
7
B uild a simple system to prove and test the Z180 MPU interfacing the SCC at 10 MHz.
Replacing the Z80 with the Z180 provides higher integration, reduced parts, more board
space, increased processing speed, and greater reliability.
INTRODUCTION
This Application Note describes the design of a system
using a Z80180 MPU (Microprocessor Unit) and a Z85C30
SCC (Serial Communications Controller), both running at
10 MHz. Hereinafter, all references are to the Z180™ and
SCC.
The system board is a vehicle for demonstration and
evaluation of the 10 MHz interface and includes the
following parts:
s Z8018010VSC Z180 MPU 10 MHz, PLCC package
s Z85C3010VSC C-MOS Z8530 SCC Serial Com-
munication Controller, 10 MHz, PLCC package
s 27C256 EPROM
s 55257 Static RAM
The Z180 is a Z80-compatible High Integration device with
various peripherals on-board. Using this device as an
alternative to the Z80 CPU, reduces the number of parts
and board space while increasing processing speed and
reliability.
The serial communication devices on the Z180 are: two
asynchronous channels and one clocked serial channel.
This means handling synchronous serial communications
protocols requires an off-chip “multi-protocol serial
communication controller.” The SCC is the ideal device for
this purpose.
Zilog’s SCC is the multi-protocol (@ 10 MHz) universal
serial communication controller which supports most serial
communication applications including Monosync, Bisync
and SDLC at 2.5 Mbits/sec speeds. Further, the wide
acceptance of this device by the market ensures it is an
“industry standard” serial communication controller. Also,
the Z180 has special numbers for system clock
frequencies of 6.144 - and 9.216 MHz which generate
exact baud rates for on-chip asynchronous serial
communication channels. This is due to the SCC’s on-
chip, 16-bit wide baud rate generator for asynchronous
ASCI communications.
The following 10 MHz interface explanation defines how
the interrupt structure works. Also included is a discussion
of the hardware and software considerations involved in
running the system’s communication board. This
Application Note assumes the reader has a strong working
knowledge of the Z180 and SCC; this is not a tutorial for
each device.
UM010901-0601
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