James C Linde

US Patent:

43731805, Feb 8, 1983

Filed:

Jul 9, 1980

Appl. No.:

6/167072

Inventors:

James P. Linde - Lafayette Hill PA

Assignee:

Sperry Corporation - New York NY

International Classification:

G06F 928
G06F 938

US Classification:

364200

Abstract:

A microprogrammed control system capable of overlapping the fetch and execution of microinstructions even when a conditional jump microinstruction is being executed. The control system comprises a pipeline register for storing the microinstruction currently being executed. The system also includes address circuitry for forming an "ordinary address" which is one greater than the address of the microinstruction in the pipeline register and for forming at least one "jump address" of a microinstruction occurring elsewhere in the program. A conditional jump microinstruction identifies a jump address for the microinstruction to be executed next, which jump address is only valid after the condition identified by the conditional jump instruction is tested and indicates that the jump address is to be used. Otherwise, the next microinstruction has an ordinary address. Selection circuitry cooperates with at least one bit signal transmitted from the anticipated condition field in the conditional jump instruction to anticipate the result of testing the condition specified and selects an address from the address circuitry for transmission to the control store memory before testing of the specified condition is complete.