DS3112
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Register Name:
T1E1DLB1
Register Description:
T1/E1 Diagnostic Loopback Control Register 1
Register Address:
54h
Bit
# 7 6 5 4 3 2 1 0
Name
DLB8 DLB7 DLB6 DLB5 DLB4 DLB3 DLB2 DLB1
Default
0 0 0 0 0 0 0 0
Bit
# 15 14 13 12 11 10 9 8
Name
DLB16 DLB15 DLB14 DLB13 DLB12 DLB11 DLB10 DLB9
Default
0 0 0 0 0 0 0 0
Note: Bits that are underlined are read-only; all other bits are read-write.
Bits 0 to 15: T1/E1 Diagnostic Loopback Enable for Ports 1 to 16 (DLB1 to DLB16).
These bits enable or
disable the T1/E1 Diagnostic Loopback (DLB). See the block diagrams in Section
1
for a visual description of this
loopback. DLB1 corresponds to T1/E1 Port 1, DLB2 corresponds to T1/E1 Port 2, and so on. If the device is
configured in Low-Speed T1/E1 Port Loop Timed mode (if LLTM bit in the MC1 register is set to a one) then only
data will be looped back—the clock will not be looped back. Since ports 4, 8, 12, 16, 20, 24, and 28 are not active
in the G.747 mode, the DLB4, DLB8, DLB12, and DLB16 bits have no effect in the G.747 mode.
0 = disable loopback
1 = enable loopback
Register Name:
T1E1DLB2
Register Description:
T1/E1 Diagnostic Loopback Control Register 2
Register Address:
56h
Bit
# 7 6 5 4 3 2 1 0
Name
DLB24 DLB23 DLB22 DLB21 DLB20 DLB19 DLB18 DLB17
Default
0 0 0 0 0 0 0 0
Bit
# 15 14 13 12 11 10 9 8
Name — —
—
—
DLB28 DLB27 DLB26 DLB25
Default — —
—
—
0 0 0 0
Note: Bits that are underlined are read-only; all other bits are read-write.
Bits 17 to 28: T1 Diagnostic Loopback Enable for Ports 17 to 28 (DLB17 to DLB28).
These bits enable or
disable the T1 Diagnostic Loopback (DLB). See the block diagrams in Section
1
for a visual description of this
loopback. DLB1 corresponds to T17 Port 17, DLB18 corresponds to T1 Port 18, and so on. Since ports 17 to 28 are
not active in the E3 mode, these bits have no effect in the E3 mode. Since ports 4, 8, 12, 16, 20, 24, and 28 are not
active in the G.747 Mode, the DLB20, DLB24 and DLB28 bits have no affect in the G.747 mode. If the device is
configured in Low-Speed T1/E1 Port Loop Timed mode (if LLTM bit in the MC1 register is set to a one), then
only data will be looped back, the clock will not be looped back.
0 = disable loopback
1 = enable loopback