Abstract:
A data processor or a data processing system used in compatible modes among which the number of bits of an address specifying a logical address space varies at the time of referring to a branch address table by extension of displacement of a branch instruction. At the time of generating a branch address of a first branch instruction, the data processor or the data processing system optimizes a multiple with which a displacement is multiplied in accordance with the number of bits of an address specifying a logical address space, adds extended address information to the value of a register, and refers to a branch address table with address information obtained by the addition. The referred information is used as a branch address. A multiple with which the displacement is multiplied can be changed in accordance with the mode.
Abstract:
The present invention provides a data processor or a data processing system which can be used in compatible modes among which the number of bits of an address specifying a logical address space varies at the time of referring to a branch address table by extension of displacement of a branch instruction. At the time of generating a branch address of a first branch instruction, the data processor or the data processing system optimizes a multiple with which a displacement is multiplied in accordance with the number of bits of an address specifying a logical address space, adds extended address information to the value of a register, and refers to a branch address table with address information obtained by the addition. The referred information is used as a branch address. To be adapted to a compatible mode using different number of bits of an address specifying a logical address space, it is sufficient to change a multiple with which the displacement is multiplied in accordance with the mode.
Abstract:
A data processing system including a processor LSI and a DRAM divided into banks, for increasing a ratio of using a fast operation mode for omitting transfer of a row address to the DRAM and for minimizing the amount of logics external to the processor LSI. The processor LSI includes row address registers for holding recent row addresses corresponding to the banks. The contents of the row address registers are compared with an accessed address by a comparator to check for each bank whether the fast operation mode is possible. As long as the row address does not change in each bank, the fast operation mode can be used, thus making it possible to speed up operations, for example in block copy processing.
Abstract:
The feature of the present invention consists in: a processor main circuit for executing program instruction strings on a processor chip; a substrate bias switching unit for switching voltages of substrate biases applied to a substrate of the processor main circuit; and an operation mode control unit for controlling, in response to the execution of an instruction to proceed to a stand-by mode in the processor main circuit, the substrate bias switching unit in such a way that the biases are switched over to voltages for the stand-by mode, and for controlling, in response to an interruption of the stand-by release from the outside, the substrate bias switching unit in such a way that the biases are switched over to voltages for a normal mode, and also for releasing, after the bias voltages switched thereto have been stabilized, the stand-by of the processor main circuit to restart the operation.
Abstract:
A main storage apparatus is a synchronous dynamic memory having a plurality of memory banks and a mode register for determining an operation mode, a main storage controller is coupled to a processor and the main storage apparatus, and means to realize controlling of parallel access to a plurality of banks of the memory and controlling of setting of an operation mode to the built-in register is arranged in the main storage controller. Accordingly, the use of a conventional processor of high generality and a conventional memory can be ensured.
Abstract:
A data processor in which a speed of an address translating operation is raised is disclosed. A translation lookaside buffer is divided into a buffer for data and a buffer for instruction, address translation information for instruction is also stored into a translation lookaside buffer for data, and when a translation miss occurs in a translation lookaside buffer for instruction, new address translation information is fetched from the translation lookaside buffer for data. A high speed of the address translating operation can be realized as compared with that in case of obtaining address translation information from an external address translation table each time a translation miss occurs in the translation lookaside buffer for instruction.
Abstract:
A multiprocessor system of the present invention has an address bus, a data bus, first and second processors, four access queues, and a shared memory divided into four banks. The four access queues are constituted by first-in first-out memories for buffering a plurality of access-request addresses transmitted through the address bus. Even if continuous access requests are addressed to one bank of the shared memory, a succeeding access request need not wait for a previous access request to be finished. Accordingly, the throughput of the system can be improved greatly.
Abstract:
The feature of the present invention consists in: a processor main circuit for executing program instruction strings on a processor chip; a substrate bias switching unit for switching voltages of substrate biases applied to a substrate of the processor main circuit; and an operation mode control unit for controlling, in response to the execution of an instruction to proceed to a stand-by mode in the processor main circuit, the substrate bias switching unit in such a way that the biases are switched over to voltages for the stand-by mode, and for controlling, in response to an interruption of the stand-by release from the outside, the substrate bias switching unit in such a way that the biases are switched over to voltages for a normal mode, and also for releasing, after the bias voltages switched thereto have been stabilized, the stand-by of the processor main circuit to restart the operation.
Abstract:
The feature of the present invention consists in: a processor main circuit for executing program instruction strings on a processor chip; a substrate bias switching unit for switching voltages of substrate biases applied to a substrate of the processor main circuit; and an operation mode control unit for controlling, in response to the execution of an instruction to proceed to a stand-by mode in the processor main circuit, the substrate bias switching unit in such a way that the biases are switched over to voltages for the stand-by mode, and for controlling, in response to an interruption of the stand-by release from the outside, the substrate bias switching unit in such a way that the biases are switched over to voltages for a normal mode, and also for releasing, after the bias voltages switched thereto have been stabilized, the stand-by of the processor main circuit to restart the operation.
Abstract:
When a leakage current of a circuit block under a non-use state is reduced by means of a power switch, frequent ON/OFF operations of the switch within a short time invite an increase of consumed power, on the contrary. Because a pre-heating time is necessary from turn-on of the switch till the circuit block becomes usable, control of the switch during an operation deteriorates a processing time of a semiconductor device. The switch is ON/OFF-controlled with a task duration time of a CPU core for controlling logic circuits and memory cores as a unit. After the switch is turned off, the switch is again turned on before termination of the task in consideration of the pre-heating time.