摘要:
A cache memory system which readily accepts software control for processing includes: a cache memory provided between a processor and memory; and a TAC (Transfer and Attribute Controller) for controlling the cache memory. The TAC receives a command which indicates a transfer and an attribute operation of cache data and a target for the operation, resulting from the execution of a predetermined instruction by the processor, so as to request the operation indicated by the command against the address to the cache memory.
摘要:
A cache memory of the present invention includes a second cache memory that is operated in parallel with a first cache memory, a judgment unit which, when a cache miss occurs in both of the first cache memory and the second cache memory, makes a true or false judgment relating to an attribute of data for which memory access resulted in the cache miss, and a controlling unit which stores memory data in the second cache memory when a judgment of true is made, and stores the memory data in the first cache memory when a judgment of false is made.
摘要:
A cache memory system which readily accepts software control for processing includes: a cache memory provided between a processor and memory; and a TAC (Transfer and Attribute Controller) for controlling the cache memory. The TAC receives a command which indicates a transfer and an attribute operation of cache data and a target for the operation, resulting from the execution of a predetermined instruction by the processor, so as to request the operation indicated by the command against the address to the cache memory.
摘要:
A cache memory of the present invention includes a second cache memory that is operated in parallel with a first cache memory, a judgment unit which, when a cache miss occurs in both of the first cache memory and the second cache memory, makes a true or false judgment relating to an attribute of data for which memory access resulted in the cache miss, and a controlling unit which stores memory data in the second cache memory when a judgment of true is made, and stores the memory data in the first cache memory when a judgment of false is made.
摘要:
The cache memory in the present invention includes a C flag setting unit 40 which adds, to each cache entry holding line data, a cleaning flag C indicating whether or not a write operation will be performed hereafter, and a cleaning unit 39 which writes back, to the memory, line data of a cache entry that has been added with a cleaning flag C indicating that a write operation will not be performed, and has been set with a dirty flag D indicating that the cache entry has been written into.
摘要:
A processor can decode short instructions with a word length equal to one unit field and long instructions with a word length equal to two unit fields. An opcode of each kind of instruction is arranged into the first unit field assigned to the instruction. The number of instructions to be executed by the processor in parallel is s. When the ratio of short to long instructions is s-1:1, the s-1 short instructions are assigned to the first unit field to the s-1tA unit field in the parallel execution code, and the long instruction is assigned to the sth unit field to the (s+k−1)th unit field in the same parallel execution code.
摘要:
A processor for decoding and executing an instruction includes: an instruction register 10 for storing an instruction; a format decoder 21 for decoding a format code located in the P0.0 field 11 of the instruction stored in the instruction register 10; a constant storage unit including a storage region; a constant register control unit 32 which, when the format decoder 21 has referred to the format code and decoded that an operation field includes a constant to be stored in the constant register 36, transfers the constant from the instruction register 10 to the constant storage unit 36; and a constant register output unit 41 which, when the format decoder 21 has referred to the format code and decoded that an operation field includes an operation code showing an operation that should be executed and a piece of an operand that should be used for the operation, links the constant stored in the constant register 36 with the piece of the operand.
摘要:
A processor (100) includes an ordinary instruction buffer (122) for storing and supplying one or more instructions fetched from an instruction cache (10), a TAR instruction buffer (123) for storing the one or more instructions fetched from the instruction cache (10) and supplying them secondarily, a selector (121) for selecting either the ordinary instruction buffer (122) or the TAR instruction buffer (123) as an instruction supplying source, and an instruction fetch control unit (102) for fetching, when a TAR filling instruction is executed, one or more instructions specified by the TAR filling instruction, and for controlling the selector (121) to select the TAR instruction buffer (123), in the case where case one or more fetched instructions are repeatedly supplied, thereby to supply an instruction through the selector (121) from the TAR instruction buffer (123).
摘要:
A processor for executing operations based on instructions includes an operation constant register 361, a branching constant register 362, a decoding unit 20 for decoding an instruction stored in an instruction register 10, a constant register control unit 32, and an execution unit 30. When the decoding unit 20 finds that the instruction includes a constant to be stored in the branching constant register 362, the constant register control unit 32 shifts a present value in the branching constant register 362 and inserts the constant to be stored, thereby storing a new constant in the branching constant register 362. When the decoding unit 20 finds that a constant is to be stored in the operation constant register 361, the constant register control unit 32 shifts the present value in the operation constant register 361 and inserts the constant to be stored, thereby storing a new constant in the operation constant register 361. When the decoding unit 20 finds that the instruction includes a branch operation, the execution unit 30 executes the branch operation using the constant stored in the branching constant register 362. When the decoding unit 20 finds that the instruction includes an arithmetic operation, the execution unit 30 executes the arithmetic operation using the constant stored in the operation constant register 361.
摘要:
A cache memory of the present invention includes: for each cache entry, way 0 to way 3 which hold use flags U indicating whether or not the use flags U have been accessed; and a control unit which: updates, when a cache entry is hit, a use flag U corresponding to the hit cache entry so that the use flag U indicates that the cache entry has been accessed; and reset, in the case where all other use flags in the same set indicates that the cache entries have been accessed herein, the all other use flags so that the use flags indicate that the cache entries have not been accessed; and select a cache entry to be replaced from among the cache entries corresponding to the use flags indicating that the cache entries have not been accessed.