Renesas CP82C89

4,5 В ~ 5,5 ВСквозное отверстие

Overview

The 82C89 Bus Arbiter operates in conjunction with the 82C88 Bus Controller to interface 80C86, 80C88 processors to a multi-master system bus (both the 80C86 and 80C88 are configured in their max mode). The processor is unaware of the arbiter’s existence and issues commands as though it has exclusive use of the system bus. If the processor does not have the use of the multi-master system bus, the arbiter prevents the Bus Controller (82C88), the data transceivers and the address latches from accessing the system bus (e.g. all bus driver outputs are forced into the high impedance state). Since the command sequence was not issued by the 82C88, the system bus will appear as “Not Ready” and the processor will enter wait states. The processor will remain in Wait until the Bus Arbiter acquires the use of the multi-master system bus whereupon the arbiter will allow the bus controller, the data transceivers, and the address latches to access the system. Typically, once the command has been issued and a data transfer has taken place, a transfer acknowledge (XACK) is returned to the processor to indicate “READY” from the accessed slave device. The processor then completes its transfer cycle. Thus the arbiter serves to multiplex a processor (or bus master) onto a multi-master system bus and avoid contention problems between bus masters.

Features • Pin Compatible with Bipolar 8289 • Performance Compatible with: - 80C86/80C88 . . . . . . . . . . . . . . . . . . . . . . . . . (5/8MHz) • Provides Multi-Master System Bus Control and Arbitration • Provides Simple Interface with 82C88/8288 Bus Controller • Synchronizes 80C86/8086, 80C88/8088 Processors with Multi-Master Bus • Bipolar Drive Capability • Four Operating Modes for Flexible System Configuration • Low Power Operation - ICCSB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10µA (Max) - ICCOP . . . . . . . . . . . . . . . . . . . . . . . . . 1mA/MHz (Max) • Operating Temperature Ranges - C82C89 . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C - M82C89 . . . . . . . . . . . . . . . . . . . . . . . .-55°C to +125°C • Pb-Free Plus Anneal Available (RoHS Compliant)

Features

Applications

• Automatic test equipment
• Precision data acquisition
• Battery-powered systems
• Sample-and-hold systems
• Communication systems
• Data Acquisition Systems
• Relay Replacement
• Battery Powered Systems
• Existing multiplexer applications (both fault-protected and
• nonfault-protected)