Pepper Computer Modular Computers RS485 - Manual (Page 46)

SMART I/O User’s Manual
March 12, 1996 ©1996 PEP Modular Computers GmbH Page 2 - 6
Chapter 2 SMART-BASE
2.3 Functional Description
Figure 2.3.0.1: SMART I/O Block Diagram
MCU
MC68302
@ 20 MHz
Memory
FLASH
EPROM
SRAM
SPI
Interface
SMART-Module
Interface
I/O Controller
Timer/Counter
Interface
DC/DC
Serial Interfaces
RS485
RS232
Clock
Generators
The MCU, an MC68302 microprocessor operating at 20 MHz is responsible
for handling all communication between the various interfaces and on-board
memory.
An RS485 highspeed PROFIBUS 2-wire interface is optically isolated from
the system and may be configured for full duplex operation (a 4-wire inter-
face available on request for OEM volume). Likewise, a fully configured
RS232 modem interface is available for program downloading for example
on SMART I/O systems supporting FLASH memory for this task or to the
RAM disk etc.