摘要:
Each of (n−1) 2-bit checking units, where n is an integer larger than or equal to 4, receives n-bit redundant encoded data generated from 1-bit input data, and outputs 2-bit check data based on a result of comparison between bits of the encoded data, combinations of the bits differing in each comparison. An all-bit checking unit outputs all-bit check data based on exclusive ORs of all-bit of the encoded data. An error detecting unit detects errors in the encoded data on the basis of the (n−1) sets of 2-bit check data and the all-bit check data, and outputs the input data on the basis of the result of error detection.
摘要:
An asynchronous interface circuit for transferring a data stream between different clock domains, the asynchronous interface circuits includes a data holding circuit for sequentially receiving and transferring data of the data stream in synchronism with a first clock signal, and holding the received data until an input of a next data, an asynchronous memory for sequentially receiving the data held in the data holding circuit in synchronism with the first clock signal and for outputting the data in the order of inputting in synchronism with a second clock signal. The asynchronous interface circuit further includes a monitor for detecting an operating state of the asynchronous memory, and a selector for selecting one of the data output from the asynchronous memory and the data output from the data holding circuit on the basis of a detecting result of the monitor.
摘要:
A control apparatus includes a capacitor to store electric power supplied from the power supply unit and to supply the stored electric power to the control apparatus when the power supply from the power supply unit is stopped, a first nonvolatile memory, a second nonvolatile memory, a first controller, and a second controller. The first controller writes the data, stored in the cache memory, into the first nonvolatile memory when the external power supply is stopped verifies whether the data stored in the first nonvolatile memory is normal, and sends information of area where the data in the first nonvolatile memory is not normal when the verification indicates that the writing is not normal. And the second controller writes the information sent from the first controller into the second nonvolatile memory.
摘要:
An asynchronous interface circuit for transferring a data stream between different clock domains, the asynchronous interface circuits includes a data holding circuit for sequentially receiving and transferring data of the data stream in synchronism with a first clock signal, and holding the received data until an input of a next data, an asynchronous memory for sequentially receiving the data held in the data holding circuit in synchronism with the first clock signal and for outputting the data in the order of inputting in synchronism with a second clock signal. The asynchronous interface circuit further includes a monitor for detecting an operating state of the asynchronous memory, and a selector for selecting one of the data output from the asynchronous memory and the data output from the data holding circuit on the basis of a detecting result of the monitor.
摘要:
A DMA circuit prevents an erroneous data transfer by a descriptor due to an address failure of memory. When a descriptor is created, the data processing unit writes a pointer, for storing the descriptor, in a predetermined part of the descriptor, and stores the descriptor in memory, and when a DMA engine reads the descriptor from the memory, the DMA engine confirms whether the value is correct, and judges whether a DMA transfer of the data in the memory is possible. For both reading and writing of a descriptor, data corruption due to an address failure can be prevented.
摘要:
A crypt processor is connected to a host computer and a storage apparatus. Data from the host computer is transferred to the crypt processor via DMA (Direct Memory Access) to be encrypted and then stored in the storage apparatus. The crypto processor acquires a descriptor defining a DMA number for identifying a DMA channel used to DMA-transfer the data. The crypto processor stores therein, based on the DMA number included in the acquired descriptor, the data transferred using the same DMA channel in units of a data size specified in a data bus. The crypto processor then encrypts the stored data in units of data size specified in a crypt system, and transfers the encrypted data to the storage apparatus.
摘要:
To be able to transmit a response packet to a target, which is the original request source node, even if, after issuing a request from a node to another, a bus ID/a device ID is replaced in the PCI-Express switch before said another node makes a response to the request source node in a PCI-Express communication system, which uses a PCI-Express switch. For that purpose, a unique node ID for indicating each node is set to the nodes, a channel ID is set to each channel used for data transfer, and the node ID of the transfer destination module, the channel ID of a channel used for the data transfer, and the packet type indicating that the packet is a request or a response are set in an address field of a packet of data transfer. For the data transfer, only a memory write request packet routed by address routing is used.
摘要:
Priorities are set in order of an internal register access packet, a response system packet, and a command system packet which are transmitted/received by a packet transmitting/receiving unit. In a transfer waiting state of the command system packet of the low priority to a certain transmission destination, in the case where the response system packet or internal register access packet of the high priority to another transmission destination is received from an external module, the packet transmitting/receiving unit withdraws the transfer waiting state and transmits the packet of the high priority.
摘要:
The present invention has been developed to carry out the dual-writing of data in cache memories at a higher speed through a single address designation for the improvement of processing performance. In the present invention, a host interface module produces addressing information for designating two written-in destinations, and a bridge module produces two transferred-to addresses and written-in addresses of the cache memories on the basis of the addressing information so that data to be written is transferred to two management modules corresponding to the two transferred-to addresses to be written at the written-in addresses of the cache memories of the management modules.
摘要:
A crypt processor is connected to a host computer and a storage apparatus. Data from the host computer is transferred to the crypt processor via DMA (Direct Memory Access) to be encrypted and then stored in the storage apparatus. The crypto processor acquires a descriptor defining a DMA number for identifying a DMA channel used to DMA-transfer the data. The crypto processor stores therein, based on the DMA number included in the acquired descriptor, the data transferred using the same DMA channel in units of a data size specified in a data bus. The crypto processor then encrypts the stored data in units of data size specified in a crypt system, and transfers the encrypted data to the storage apparatus.