Microprogram sequence controller.

摘要

A one-chip, integrated-circuit, microprogram sequence controller for use in a microprogrammed system having a data processing unit and a microprogram memory, that controls the order and execution of microinstructions within the microprogram memory. The controller is provided with two 16-bit microinstruction address input busses and a 16-bit output bus on which microinstruction addresses are issued to the microprogram memory. One of the input busses and the output busses are bidirectional providing access to various on-chip parameters such as the contents of the top of an on-chip stack memory or the value of an on-chip stack pointer. An on-chip comparator permits trapping of a microinstruction at a specified address or gathering of run-time statistics. A structured, 64-element instruction set is provided which includes sixteen special-function continue instructions which perform additional operations without imposing added time requirements. A set of multiway instructions are provided affording selection of alternative multiway branch addresses from four 4-bit data inputs to the controller.