Processor including incrementor and program register structure

摘要

A processor including a first bus, a second bus, and a control circuit for producing control signals includes a counter having a plurality of inputs and outputs responsive to the control circuit and coupled between the first and second buses for incrementing digital information present at the inputs of the counter. The processor includes a first coupling circuit responsive to the control circuit for coupling the counter inputs to the first bus to effect transferring digital information from the first bus to the counter inputs. A second coupling circuit couples the counter inputs to the second bus to transfer digital information from the second bus to the counter inputs in response to the control circuit. A third coupling circuit couples the counter outputs to the second bus to transfer digital information from the counter output to the second bus. When the second and third coupling circuits are both simultaneously activated in response to the control circuit, digital information present at the counter inputs is effectively latched and temporarily stored in the circuit formed by the counter and the second and third coupling circuits. The processor also includes a program register coupled between the first and second buses for temporarily storing digital information received from the counter means by means of a fourth coupling circuit, which operatively couples the outputs of the counter to inputs of the program register to effect transferring digital information from the counter outputs to the program register inputs in response to the control circuit. Fifth and sixth coupling circuits operatively couple the program register outputs to the first or second bus in response to the control circuit to effect transferring digital information from the program register to the first or second buses, respectively.