Datasheet

DS21Q59 Quad E1 Transceiver
24 of 76
Register Name:
CCR5
Register Description:
Common Control Register 5
Register Address:
16 Hex
Bit # 7 6 5 4 3 2 1 0
Name LIUODO CDIG LIUSI IRTSEL TPRBS1 TPRBS0 RPRBS1 RPRBS0
NAME BIT FUNCTION
LIUODO 7
Line Interface Open-Drain Option. This control bit determines whether or not the
TTIP and TRING outputs are open drain. The line driver outputs can be forced
open drain to allow 6V
PEAK
pulses to be generated or to allow the creation of a very
low power interface.
0 = allow TTIP and TRING to operate normally
1 = force the TTIP and TRING outputs to be open drain
CDIG 6
Customer Disconnect Indication Generator. This control bit determines whether
the line interface generates an unframed ...1010... pattern at TTIP and TRING
instead of the normal data pattern.
0 = generate normal data at TTIP and TRING
1 = generate a ...1010... pattern at TTIP and TRING
LIUSI 5
Line Interface G.703 Synchronization Interface Enable. This control bit works
with CCR7.0 to select G.703 functionality on the transmitter and receiver (Table
8-B
). These bits determine whether the line receiver and transmitter should
receive/transmit a normal E1 signal (Section 6 of G.703) or a 2.048MHz
synchronization signal (Section 10 of G.703).
IRTSEL 4
Receive Termination Select. This function applies internal parallel resistance to
the normal 120W external termination to create a 75W termination.
0 = normal 120W external termination
1 = internally adjust receive termination to 75W
TPRBS1 3
Transmit PRBS Mode Bit 1
TPRBS0 2
Transmit PRBS Mode Bit 0
RPRBS1 1
Receive PRBS Mode Bit 1
RPRBS0 0
Receive PRBS Mode Bit 0
Table 8-B. G.703 Function
LIUSI
(CCR5.5)
TG703
(CCR7.0)
FUNCTION
0 0 Transmit and receive function normally
0 1 Transmit G.703 signal, receiver functions normally
1 0 Transmit and receive G.703 signal
1 1 Receive G.703, transmitter functions normally