Samsung OFFICESERV 7100 Service Manual page 69

Controls two TP3404 chips.(A total of 16 channels are available.)
Recognizes the used board and ID.
A master clock of 4.096 MHz is used.
Operates at 5 V.
60-pin Quad Flat Pack(QFP) is used.
QDASL Interface
This interface is a D channel of each port, and RxD and TxD exist for serial data transfer.
AMI codes created along with B channels are transmitted to the line and the D-channel data
are used for controlling phones. The B-channel data are used for generating voice signals.
/INTD processes the micro-channel interrupt of QDASL in each port. The INT of the
QDASL is generated only when accessing the micro channel and initializing the QDASL.
The INT is generated in the event of NO SIGNAL(CO), OUT OF SYNC(C1), and BIPOLAR
VIOLATION(C7).
The INT is bundled up of UART Tx INT and AND GATE only when power is on for the
first time and the QDASL status is changed by an error in the phone. The INT is a clock in
the μ-CH controlling part that sets the initial QDASL status of the port and is configured
with CCLK(1 MHz), CI for entering controlling data, and CO for displaying status.
Also, B channel is synchronized into hardware frame allocated to itself and is transmitted
to the QDASL by opening the hardware buffer. The control data are transferred to the sub-
time slot, which is D-channel where 256 channels of 2-bit are allocated. The sub-time slot
means that the B channel of 8-bit is divided into four. To receive D channel data of 1 byte
from the QDASL, the data of 4 frames should be received first.
QDMC provides 128 sub-time slots.
Digital Phone Interface
The AMI code is created from the QDASL(TP3404) and is transmitted to regular phones
through the Trans. The serial data are transferred to the QDMC by demodulating the AMI
code received from the phone through the Trans. The QDMC converts the entered serial data
to parallel data through the UART and transfers the data to the CPU. Also, /TSB of the QDASL
transfers the voice data of DASL to the highway.
Since one QDMC controls two QDASLs(a total of 8 ports), the /TSB signals generated
from each QDASL are added for use.
DLT-1 is used for a Trans for matching, and resistance of 100Ω in the QDASL LO adjusts
impedance. 2μF reduces noises. Two Zener diodes(3.6 V) in the Trans input part prevent hazard.
The power of -56V is supplied to the phone through the Poly switch to prevent over-current
from flowing to the phone. The varistor in the Trans input part prevents hazard.
Transmission Part
This part is a circuit part through which data(D-channel) and voices(B-channel) are
transferred between the digital phone and 8DLI board in a full-duplex method. The 8DLI
board operates in master mode and digital phones operate in slave mode. Once data are
transferred in master mode, the data are received and then, are transferred in a guard time
© SAMSUNG Electronics Co., Ltd.
OfficeServ 7100 Service Manual
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