Datasheet

DS21Q50
31 of 87
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 the TTIP and
TRING outputs are open drain or not. 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 determines
whether the line receiver should handle a normal E1 signal (Section 6 of G.703) or a
2.048MHz synchronization signal (Section 10 of G.703). This control has no affect on
the line interface transmitter.
0 = line receiver configured to support a normal E1 signal
1 = line receiver configured to support a synchronization signal
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 (Table 8-1)
TPRBS0 2 Transmit PRBS Mode Bit 0 (Table 8-1)
RPRBS1 1 Receive PRBS Mode Bit 1 (Table 8-2)
RPRBS0 0 Receive PRBS Mode Bit 0 (Table 8-2)