Method and system for programmable boundary-scan instruction register
AssigneeXilinx, Inc.
InventorNeil G. Jacobson
Life of this patent
Estimating the term…
Abstract
A flexible architecture for extending the instruction set for a boundary-scan interface. An instruction can be selected from a memory store (308) and decoded by a decoder (310). The instruction can subsequently be shifted into an instruction register (349) where it can be executed. Alternatively, a length of an existing instruction register (382) of a boundary-scan interface can be programmably appended to effectively increase the length of the register. A plurality of serially arranged bit registers (376, 378, 380) can be connected in series with the existing instruction register. By selecting an outer one of the serially arranged bit registers, the length of the existing instruction register can be extended.
Claims20
A method for extending an existing instruction set for a boundary-scan interface, the method comprising:
- providing a programmable instruction register for enabling a variable number of instructions of an instruction set;
- storing at least one new instruction in a memory of the boundary-scan interface to extend the existing instruction set of the boundary scan interface;
- loading one of said at least one new instruction from said memory into a decoder;
- decoding said new instruction loaded into said decoder;
- and
- causing execution of a new task.
A method for flexibly programming a length of an existing instruction register in a boundary-scan interface, the method comprising:
- providing a plurality of serially arranged bit registers, said serially arranged bit registers programmably connected in series with the existing instruction register of the boundary-scan interface;
- and
- enabling one outer bit register from said plurality of serially arranged bit registers, said enabled outer bit register enabling all subsequent bit registers between said outer bit register and the existing register, thereby flexibly programming the length of the boundary-scan interface instruction register.
A system for extending an existing instruction set for a boundary-scan interface, the system comprising:
- means for programmably enabling a variable number of instructions of an instruction set;
- means for storing at least one new instruction in a memory of the boundary-scan interface;
- means for loading one of said at least one new instruction from said memory into a decoder;
- means for decoding said new instruction loaded into said decoder;
- and
- means for causing the execution of a new task.
A system for flexibly programming a length of an existing instruction register in a boundary-scan interface, the system comprising:
- a plurality of serially arranged bit registers, said serially arranged bit registers programmably connected in series with the existing instruction register of the boundary-scan interface;
- and
- means for enabling one outer bit register from said plurality of serially arranged bit register, said enabled outer bit register enabling all subsequent bit registers between said outer bit register and the existing register, thereby flexibly programming the length of the boundary-scan interface instruction register.
Dependencies are inferred from the claim text.