摘要:
A transmission network is comprised of a network management system for collectively managing and controlling a plurality of transmission devices coupled mutually through transmission routes and the transmission network as well. The network management system includes a plane management table adapted to manage transmission planes defined as a set of paths in the transmission network, and the plane management table has the function to set and manage a transmission plane (working plane) applied during normal operation and besides, a single or a plurality of transmission planes (protection planes) applicable in the event of occurrence of a fault in the transmission network. Then, when a fault occurs in the transmission network, the network management system changes the applied plane to a suitable transmission plane.
摘要:
When data is disclosed to a plurality of users by using a transfer network and a transfer apparatus, data disclosure time control which cannot be adversely affected by the users is performed to reduce the difference in data disclosure time among the users. A transfer network system includes a distribution server serving as a data-distribution-source transfer apparatus, and a network terminal connected to distribution-destination user equipment. The distribution server and the network terminal each have a time keeping function and a time synchronization function for matching the time of the time keeping function with a master clock. The distribution server sends in advance disclosure data and disclosure time to the network terminal. When the time of the time keeping function of the network terminal matches the disclosure time, the network terminal sends the disclosure data to the user equipment.
摘要:
The OLT manages information of optical intensity and communication bit rate receivable by each ONU, and transmits a signal at suitable optical intensity and a bit rate. The OLT decides a signal transmission plan for each ONU according to a status of accumulated information waiting to be transmitted in the OLT's own device buffer, and inserts the signal transmission plan in a header or payload of a downlink frame, thereby notifying the ONUs of the information prior to transmitting accumulated information (primary signal). The ONU recognizes the signal transmission plan of the OLT according to the time information in a downlink intensity map, receives only a signal having the optical intensity and bit rate suitable for the ONU's own device, and blocks other signals.
摘要:
When a neighbor ONU receives a signal with light intensity high enough to secure communication between an OLT and a remote ONU, the light intensity may be excessively high to damage a receiver of the neighbor ONU. In order to avoid such a problem, each ONU is notified of a downstream signal transmission plan (downstream light intensity map) prior to transmission of a downstream signal. Each ONU receives the downstream light intensity map (light intensity transmission schedule of downstream signal) in advance. Thus, the neighbor ONU can block or attenuate an optical signal addressed to the remote ONU, and the remote ONU can determine normal operation even when the remote ONU cannot receive a signal addressed to the neighbor ONU. Thus, the remote ONU can be prevented from issuing a wrong error signal.
摘要:
An internal voltage generator when activated, generates an internal voltage to be supplied to an internal circuit. Operating the internal voltage generator consumes a predetermined amount of the power. In response to a control signal from the exterior, an entry circuit inactivates the internal voltage generator. When the internal voltage generator is inactivated, the internal voltage is not generated, thereby reducing the power consumption. By the control signal from the exterior, therefore, a chip can easily enter a low power consumption mode. The internal voltage generator is exemplified by a booster for generating the boost voltage of a word line connected with memory cells, a substrate voltage generator for generating a substrate voltage, or a precharging voltage generator for generating the precharging voltage of bit lines to be connected with the memory cells.
摘要:
An internal voltage generator when activated, generates an internal voltage to be supplied to an internal circuit. Operating the internal voltage generator consumes a predetermined amount of the power. In response to a control signal from the exterior, an entry circuit inactivates the internal voltage generator. When the internal voltage generator is inactivated, the internal voltage is not generated, thereby reducing the power consumption. By the control signal from the exterior, therefore, a chip can easily enter a low power consumption mode. The internal voltage generator is exemplified by a booster for generating the boost voltage of a word line connected with memory cells, a substrate voltage generator for generating a substrate voltage, or a precharging voltage generator for generating the precharging voltage of bit lines to be connected with the memory cells.
摘要:
A word control circuit activates word lines corresponding to a start row address and a next row address overlappingly in the continuous mode. Accordingly, even in the case where the start address indicates an end memory cell connected to a word line, the switching operation of the word line becomes unnecessary. Memory cells connected to different word lines can be thus accessed in a sequential manner. That is, a controller accessing a semiconductor memory device can access the memory without data interruption. This can prevent the data transfer rate from lowering. Furthermore, it is made unnecessary to form a signal and a control circuit for informing a controller of the fact that a word line is being switched so that the construction of a semiconductor memory device and a control circuit of the controller can be simplified. This results in reduction of the system cost.
摘要:
A semiconductor memory is provided, the semiconductor memory including a memory core that includes a plurality of memory cells, a refresh generation unit that generates a refresh request for refreshing the memory cell, a core control unit that performs an access operation in response to an access request, a latency determination unit that activates a latency extension signal upon a conflict between activation of a chip enable signal and the refresh request and that deactivates the latency extension signal in response to deactivation of the chip enable signal, a latency output buffer that outputs the latency extension signal, and a data control unit that changes a latency from the access request to a transfer of data to a data terminal during the activation of the latency extension signal.
摘要:
A data transfer method and system are provided that prevent the length of a time required for writing to a flash memory from appearing on the surface as a system operation when the flash memory is used in place of an SRAM. The method of transferring data includes the steps of writing data from a controller to a volatile memory, placing the volatile memory in a transfer state, transferring the data from the volatile memory in the transfer state to a nonvolatile memory, and releasing the volatile memory from the transfer state in response to confirming completion of the transfer of the data.
摘要:
A burn-in test, including first to sixth steps where voltages are applied for the same lengths of time in each step, is applied to a semiconductor memory having alternately arranged bit line pairs with twist structure where the bit lines cross each other and bit line pairs with non-twist structure where the bit lines are parallel to each other. Since lengths of time in which a stress is applied for all bit lines can be equally set, no deviation occurs in lengths of time where stress is applied between the bit lines. Characteristics of memory cells can be prevented from excessively deteriorating from the burn-in test. Further, the number of bit lines not having stress applied can be minimized in the first to sixth steps. Accordingly, the ratio of the bit lines having stress applied can be increased, which reduces the burn-in test time. Thus, test cost can be reduced.