Abstract: There is provided a microprocessor system that can execute a specific set of instructions at a high speed while limiting the increase in size of the circuitry. The microprocessor system, which executes instructions described in a program, comprises a main processor which executes a first set of instructions by means of hardware and executes a second set of instructions by means of software and a co-processor which operates under the control of the main processor to execute the second set of instructions by means of hardware. When the co-processor encounters a specific instructions of the second set for which data under the control of the main processor needs to be operated, the co-processor issues a notification of this fact to the main processor to request it to execute the specific instruction. In this case, the co-processor updates its stack pointer and program counter by itself by means of hardware.

Abstract: Micro-computer capable of independently testing an additional logic for user and a pre-existing micro-computer portion in a shipment test of the micro-computer having the enclosed additional logic for user. A logic dedicated to connection is directly coupled to an internal bus of the micro-computer and is provided between the additional logic for user and the micro-computer. For testing the additional logic for user, a bus/port changeover terminal of the micro-computer and a read/write signal are used to effect readout/writing. Also, a bus inspection register is provided in the logic dedicated to connection. For testing the micro-computer, an output of the inspection register is read out to a bus of the logic dedicated to connection to inspect the bus.

Abstract: A new animal feed composition which comprises bicyclomycin and a new method for promoting the growth of animals, which comprises oral administration of the same to animals.