CHAPTER 1.Overview OfficeServ 500 Wireless LAN Service Manual/Ed.00Page 1-10 © SAMSUNG Electronics Co., Ltd.SRAMTwo SRAMs of 256 Kbyte X 2 capacity are used, and they operate with the CPU onthe 16 bits mode for transmitting/receiving data. The KM684000LT of SAMSUNG isused.Asynchronous Dual Port RAMThe DPRAM is used for data transmission with the main board of OfficeServ 500system.The components used for IPC(Inter-processor communication) are the CY7C136-55NC of Cypress, and this can read/write 2Kbyte data at the same time.DMC (Digital Module Control)The 8WLI has 16 DASL links. To control these, one DMC chip is used for 8 DASLs.Therefore, a total of 2 DMC components are used, and the used components areSTL7052E SAMSUNG ASIC. They can handle interrupts and process data channeltransmission. The major functions are described as follows :y The DMC buffers serial data from 8 DASL transmission chips and transferred tothe CPU, and serially transfers the transmission data from the CPU to eachDASL.y The DMC muxes the interrupts occurred at the initial activation of DASL to sendone source to the CPU, and saves the event changes for each DASL transmissionchip.y The DMC assigns highway timeslot for each DASL chip to be able to program.DASL (Digital Adapter Subscriber Loops)The wired interface between the 8WLI and AP(WBS24) uses the DASL componentsof NS. One DASL link has the transmission speed at 144kbps, and there are 2B+1D 2voice channels and one data channel. Since two DASLs for each WBS24 are used,there are 4B+2D, 4 voice channels and 2 data channels. However, only one datachannel from 2 data channels are used, leaving the one at rest. Also, the transmissionspeed of data channel is set at 16 kbps.The DASL link is connected to two wired cables, so each AP(WBS24) is connectedto 4 wired cables. The 24AWG UPT(Unshielded Twisted Pair wire) cable is used,and the maximum extension distance is 600M.Echo Canceller (ZL50232)Impedance might be mismatched or line echo might occur due to delay during dataprocessing in the hybrid system. To remove the echo, add the Echo Canceller in thevoice path. The default of the echo tail(echo length) is 64 ms and the echo tail can beexpanded to 128 ms.
