Mgi Board; Figure 4.15 Mgi Block Diagram - Samsung OfficeServ 12 Service Manual

PEB 3086 (ISDN Subscriber Access Controller ISAC)
The PEB 3086 ISAC implements the four-wire S/T interface used to link voice/data
terminals to ISDN. The PEB 3086 combines the functions of the S-Bus Interface Circuit
and the ISDN Communications Controller on one chip. The component switches B and D
channels between the S/T and the IOM interfaces, the latter being a standard backplane
interface 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 priority
control. The HDLC(High-level Data Link Control procedure) packets of the ISDN D
channel 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 of
the LAPD(Link Access Procedure on D channel) protocol. It operates from a single +3.3 V
supply and features a power-down state with very low power consumption.
Analog PLL
Analog PLL contains a circuit that locks 8 KHz sync signal generated by the 2BRI board, and
generates 4 MHz clock and /FOI foe used as a reference clock for implementing Multi-ISDN.

4.2.4 MGI Board

A 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:
40P
CONNECTOR
X 2EA
•
Device: Audio Codes AC 48204
• Memory Size: 4 Byte(HPI Interface)
•
Quantity: 1
•
Power: 3.3 V
•
Package: 144P TQFP
•
Bus Bandwidth: 8 Bits
© SAMSUNG Electronics Co., Ltd.
Voice/FAX Compressing part
Address bus
VOIP Processor AC 48204
Data bus
CS, 2M, FSX, Reset
Highway, DTA, R/W
AS, Interrupt

Figure 4.15 MGI Block Diagram

G.723/G.729
SRAM
64K X 16Bit
KM616V1002BT
22