British Telecommunications Engineering Volume 7 page 77

All-CMOS High-Temperature STEbus

The first all-CMOS processor board for the STEbus has been announced by British Telecom Microprocessor Systems. Based on Intel’s 8031 CPU with CMOS memory and input/output (I/O), the minimal power consumption and inherent noise immunity of the board makes it ideally suited to the implementation of computer systems for battery- powered or harsh-environment applications.

The board, designated the 4040-00 , accepts up to 32K ROM and 32K RAM, and offers 24 lines of digital I/O, two 16 bit counter-timers, two external interrupts, a battery-backed real-time clock with watch-dog timer, and power-fail circuitry. I/O facilities are brought out on a ribbon-cable connector conforming to the STE industry-standard ‘signal-conditioning bus’ scheme, which allows connection to a wide variety of real-world off-the-shelf interfaces.

The 4040-00 operates over -40 to +85°C, working from a single 5 V supply and consuming just 40 mA. Combined with CMOS technology’s excellent noise immunity, the board is an ideal basis for the design of computer system applications such as remote data loggers, factory-floor data collection terminals or portable test instrumentation. Remote applications are supported by BT’s STEbus modem for connection to the public-switched telephone network.