Abstract: A switching system for controlling internal apparatuses provided within an exchange system includes a central controller and a switching module including a plurality of objective apparatuses, each objective apparatus including a control data end unit, controlled by the central controller based on DMA communication and SD/SCN signal. Further, the central controller includes a first processor access controller which transfers control data to the control data end unit, in order to check and control each of objective apparatus, based on the DMA communication and the SD/SCN signal. The switching module includes a second processor access controller which relays the control data transferred between the first processor access controller and a plurality of control data end units-based on the DMA communication and the SD/SCN signal.

Abstract: A duplex memory control apparatus having a first control unit containing a first memory and a second control unit containing second memory, a first control unit and a second control unit connected to each other through a bus.

Abstract: An exchange equipment using STM able to achieve an improvement of an efficiency of use and an improvement of ease of increase of terminal cards, that is, an STM type exchange, including a time switch, for performing exchange processing of time division multiplexed data, wherein a ring highway is connected via a terminal common unit to an upstream highway and a downstream highway coupled to this time switch via a highway interface unit or directly and wherein a plurality of terminal cards are connected to this ring highway. Each terminal card is provided with an add/drop unit which drops and adds the data from and to an assigned time slot on the ring highway according to control information indicating time slot assignment information determined by the control unit and adds the data and with a card control unit which controls the add/drop unit.