2.2 Components Used

The CF32006 Triple Incremental Encoder Interface Chip consists of three identical incremental encoder interface circuits. This encoder interface can be configured into one of three operating modes: direction discrimination with five modes of counter incrementation, pulse width measurement, and frequency measurement.

The MC68153 Bus Interrupter Module (BIM) is designed to serve as an interrupt requester for peripheral devices in a microprocessor system. An interrupt request from any device is routed to the MC68153, and the BIM handles all interfacing to the VMEbus. It generates a bus interrupt request as a result of the device interrupt request. When the system interrupt handler responds with an interrupt acknowledge cycle, the MC68153 can answer supplying an interrupt vector and handle all timing.

Two Field Programmable Gate Array (FPGA) devices are used to monitor and synchronise the differential input signals to the CF32006 devices. The FPGA devices also contain all the group functions that are not provided by the CF32006 and the MC68153 devices.