Microprocessor with reduced microcode space requirements due to improved branch target microaddress circuits, systems, and methods
AssigneeTexas Instruments Incorporated
InventorsJames O. Bondi, Jonathan H. Shiell
Life of this patent
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Abstract
A circuit (10) for producing a microprogram memory address (16). This circuit includes circuitry (18I, 18J) for selecting a plurality of condition codes. Additionally, the circuit includes logic circuitry (20) for producing a result by performing logic operations using as operands the selected plurality of condition codes. The result of the logic operations forms a first portion (LSB', or LSB' and NLSB') of the microprogram memory address.
Claims38
A circuit for producing a microprogram memory address, said circuit comprising:
- circuitry for selecting a plurality of condition codes;
- and
- logic circuitry for producing a result by performing logic operations using as operands the selected plurality of condition codes, wherein the result forms a first portion of the microprogram memory address.
A processor, comprising:
- a microprogram memory for outputting a microprogram memory instruction in response to a microprogram memory address;
- a circuit for producing the a microprogram memory address, said circuit comprising:
- circuitry for selecting a plurality of condition codes;
- and
- logic circuitry for producing a result by performing logic operations using as operands the selected plurality of condition codes, wherein the result forms a first portion of the microprogram memory address.
A microprocessor-based computer system, comprising:
- an input device;
- a display system;
- a main memory;
- and
- a microprocessor, coupled to the input device, display system and main memory, and comprising:
- a microprogram memory for outputting a microprogram memory instruction in response to a microprogram memory address;
- a circuit for producing the microprogram memory address, said circuit comprising:
- circuitry for selecting a plurality of condition codes;
- and
- logic circuitry for producing a result by performing logic operations using as operands the selected plurality of condition codes, wherein the result forms a first portion of the microprogram memory address.
A method of producing a microprogram memory address, comprising the steps of:
- selecting a plurality of condition codes;
- and
- producing a result by performing logic operations using as operands the selected plurality of condition codes, wherein the result forms a first portion of the microprogram memory address.
Dependencies are inferred from the claim text.