Microprocessor-based computing system - uses hard-wired arithmetic logic unit together with flexible control unit to allow user to code macro instructions

摘要

A microprocessor based computing system has a hand wired arithmetic logic unit with a flexible control unit that allows the user a choice in the way in which macro instructions are coded. The system has a control unit consisting of a micro programme control stage providing the sequence of addresses to access a micro programme memory. Data from the memory is transmitted to the arithmetic logic unit. This operates with macro instructions in higher level language format held in the programme memory. Each macro has a corresponding group of micro instructions that are accessed in the micro programme store. Control signals identifying the micro instructions are latched into flip-flops in the control lines connecting with the control unit.