Floating Point Coprocessors

Part I of Essay
The designer of any microprocessor would like to extend its instruction set almost infinitely but is limited by the quantity of silicon available (not to mention the problems of testability and complexity). Consequently, a real microprocessor represents a compromise between ....

Part II of Essay
.... be as simple as possible and require a minimum overhead in terms of both hardware and software. There are various techniques of arranging a coprocessor alongside a microprocessor. One technique is to provide the coprocessor with an instruction interpreter and program counter. Each instruction fetched from memory is examined by both the MPU and the coprocessor. If it is a MPU instruction, the MPU executes it; otherwise the coprocessor executes it. It can be seen that this solution is feasible, but by no means simple, as it would be diff ....