Zilog Z80230 - Manual (Page 217)

SCC/ESCC
User Manual
UM010903-0515 Application Notes
210
AN0096: The Z180 Interfaced with the SCC at 10 MHz
Abstract
This Application Note describes how to build a simple system to prove and test Zilog’s Z180
Microprocessor Unit (MPU) interfacing Zilog’s Serial Communications Controller (SCC) at 
10 MHz. Replacing Zilog’s Z80 ® with the Z180 provides higher integration, reduced parts, more
board space, increased processing speed, and greater reliability.
It also describes the design of a system using Z80180 MPU and Z85C30 SCC, both running at 10
MHz. Hereinafter, all references are to the Z180 and SCC.
Features
The system board is a vehicle for demonstration and evaluation of the 10 MHz interface and
includes the following parts:
• Z8018010VSC Z180 MPU 10 MHz, PLCC package
• Z85C3010VSC C-MOS Z8530 SCC, 10 MHz, PLCC package
• 27C256 EPROM
• 55257 Static RAM
Discussion
Zilog’s 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 include:
1. Two asynchronous channels.
2. One clocked serial channel.
This means handling synchronous serial communications protocols requires an off-chip ‘multi-
protocol SCC.’ The SCC is the ideal device for this purpose.
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 Mbps
speeds. Further, the wide acceptance of this device by the market ensures it is an ‘industry stan-
dard’ SCC. 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 commu-
nications.
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 sys-
tem’s communication board. This application note is written for a reader with strong working
knowledge of the Z180 and SCC. It is not a tutorial for each device.