Central processing unit and microcomputer system having an internal operation unit for cryptographic
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorHiroaki Suzuki
Life of this patent
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Abstract
A central processing unit capable of solving a problem of a conventional one in that when a user tries to implement a cryptographic function unique to the user using the conventional central processing unit, it is necessary to connect an external operation unit through a bus, and this imposes a heavy development load on the user. The present central processing unit has, in an operation block performing operations based on a register file which operational instructions can directly refer to, an operation unit having a facility which provides the user with capability of setting its operational function.
Claims19
A central processing unit comprising:
- an operational block including a register files to which an operational instruction can refer, said operation block performing an operation on input data including data set in said register file;
- and
- a controller for controlling said operation in response to the operational instructions,
- said operational block includes an operation unit for achieving a cryptographic processing, said operation unit having a facility which provides capability of changing an operation required for said cryptographic processing to another operation required for said cryptographic processing.
A central processing unit comprising:
- an operation block including a register file to which an operational instruction can refer, said operation block performing an operation on data set in said register file;
- and
- a controller for controlling said operation unit to perform the operation in response to the operation instruction, wherein
- said operation block further includes:
- first, second and third data lines, each connected to said register file;
- an operation unit connected to said first to third data lines and capable of performing a plurality of operations using data transferred on at least one of said first and second data lines, respective results of said plurality of operations being output to said third data line;
- and
- a store circuit connected to said first data line and storing information specifying one of said plurality of operations transferred on said first data line, said operation unit selecting and performing the specified operation in response to the information in said store circuit.
Dependencies are inferred from the claim text.