摘要:
A system for controlling the DMA transfer for a plurality of IO devices has an IO controller for each group of the IO devices. Data is retrieved from memory and stored in the IO controller where it is analyzed. The retrieved data has a structure that permits a group of DMA start request quads to be linked together for parallel or pipeline processing of the DMA transfer requests. Each start request quad has a pointer for additionally retrieving corresponding command data. The command data is set forth in a number of blocks, each linked to the next one by a pointer. When a DMA processing has been completed, the termination or completion status is entered into a specific entry in a completion list for the corresponding IO device. Thus, a determination can be made as to whether specific IO devices have completed a requested DMA processing. Expansion of the system is accomplished by using combinations of main and sub controllers, where one main controller provides the aforementioned data structures for many sub controllers in order to enable the DMA processing to be performed for IO devices connected to the sub controllers with less frequent access of system main memory and the system bus.
摘要:
A novel and improved control and supervisory system for power distribution equipment including a plurality of terminal control and/or supervisory devices each capable of controlling and/or supervising a plurality of power distribution devices in an extremely simple, high-speed and efficient manner without requiring any central control and/or supervisory unit. To such control and/or supervisory operation, no vast and full knowledge of permitted and inhibited operations of varying kinds of power distribution devices connected therewith, as well as of the control and supervisory procedures therefor, is required. To these ends, each of the terminal control devices comprises a control and/or supervisory instruction section operable to output a control or supervisory command for controlling or supervising a plurality of power distribution devices, and a control and/or supervisory section operable to receive the control or supervisory command from the control and/or supervisory instruction section for generating a control or supervisory signal suited to control or supervise a corresponding one of the power distribution devices, and outputting it to the corresponding power distribution device. In one embodiment, the control or supervisory command is conceptually common to the power distribution devices. In another embodiment, the control and supervisory command is intrinsic to a corresponding one of the power distribution devices. Thus, there is no need for a sender terminal device to prepare specific control and supervisory programs suited to the respective power distribution devices.
摘要:
A level conversion circuit includes first to nth circuits, each having an input terminal and first to nth output terminals where n is an integer, and first to nth signal lines coupled to the first to nth circuits. Each of the first to nth circuits comprises a part for outputting a first voltage to the first output terminal and outputting a second voltage to the second to nth output terminals other than the first output terminal when an input signal applied to the input terminal is at a first level and for maintaining the first to nth output terminals in high-impedance states when the input signal is at a second level different from the first level. The first output terminal of each of the first to nth circuits is connected to one of the first to nth signal lines so that first output terminals of the first to nth circuits are connected to mutually different signal lines. The second to nth output terminals of each of the first to nth circuits are connected to (n-1) signal lines other than the one of the first to nth signal lines to which the first output terminal is connected.
摘要:
A diaphragm for a dynamic cone speaker which is composed of a porous metal produced from nickel powder wherein a vinyl chloride sheet is disposed on the surface of the porous metal to eliminate the gas permeability of the porous metal.