Samsung OfficeServ 12 Service Manual

Also see for OfficeServ 12: General description

© SAMSUNG Electronics Co., Ltd. 22PEB 3086 (ISDN Subscriber Access Controller ISAC)The PEB 3086 ISAC implements the four-wire S/T interface used to link voice/dataterminals to ISDN. The PEB 3086 combines the functions of the S-Bus Interface Circuitand the ISDN Communications Controller on one chip. The component switches B and Dchannels between the S/T and the IOM interfaces, the latter being a standard backplaneinterface for the ISDN basic access.The device provides all electrical and logical functions of the S/T interface, such as;activation/deactivation, mode dependent timing recovery and D channel access and prioritycontrol. The HDLC(High-level Data Link Control procedure) packets of the ISDN Dchannel are handled by ISAC-S, which interfaces them to the associated microcontroller.In one of its operating modes the device offers high-level support of layer-2 functions ofthe LAPD(Link Access Procedure on D channel) protocol. It operates from a single +3.3 Vsupply and features a power-down state with very low power consumption.Analog PLLAnalog PLL contains a circuit that locks 8 KHz sync signal generated by the 2BRI board, andgenerates 4 MHz clock and /FOI foe used as a reference clock for implementing Multi-ISDN.4.2.4 MGI BoardA MGI daughter board can be equipped on the base board of OfficeServ 12.The MGI board converts voice to data, which is exchanged through a data network.The MGI board provides up to four channels, and supports voice CODEC of G.729, G.723,G.726, and G.711.The blocks of the MGI board are shown in the figure below:Figure 4.15 MGI Block Diagram• Device: Audio Codes AC 48204• Memory Size: 4 Byte(HPI Interface)• Quantity: 1• Power: 3.3 V• Package: 144P TQFP• Bus Bandwidth: 8 Bits40PCONNECTORX 2EAVoice/FAX Compressing partG.723/G.729VOIP Processor AC 48204SRAM64K X 16BitKM616V1002BTAddress busData busCS, 2M, FSX, ResetHighway, DTA, R/WAS, Interrupt