
PM5317 SPECTRA-9953 Telecom Standard Product Data Sheet
Release
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2000741, Issue 5
158
Register 0019H: SP9953 System Loopback Configuration
Bit
Type
Function
Default
Bit 15
R/W
Unused
0
Bit 14
R/W
Unused
0
Bit 13
R/W
Unused
0
Bit 12
R/W
Unused
0
Bit 11
R/W
SDLB[4]
0
Bit 10
R/W
SDLB[3]
0
Bit 9
R/W
SDLB[2]
0
Bit 8
R/W
SDLB[1]
0
Bit 7
R/W
Reserved
0
Bit 6
R/W
Reserved
0
Bit 5
R/W
Reserved
0
Bit 4
R/W
Reserved
0
Bit 3
R/W
LSSLB[4]
0
Bit 2
R/W
LSSLB[3]
0
Bit 1
R/W
LSSLB[2]
0
Bit 0
R/W
LSSLB[1]
0
The System Loopback Register is provided at SP9953 Read/Write Address 19H.
LSSLB[1:4]
The Line side/system Loopback (LSSLB[N]) bits enable the LSSLB for the N
h
STS-48/STM-16 slice. When a logic 1 is written to LSSLB[N], the Transmit TRMP data of
STS-48/STM-16 slice N is looped back into the Receive RRMPdata of STS-48/STM-16
slice N. When a logic 0 is written to LSSLB[N], the line side/system loopback is inactive.
Note that while enabling LSSLB[n], the Receive Overhead Port is not reliable and should
not be used.
SDLB[1:4]
The System Diagnostic Loopback (SDLB[N]) bits enable the SDLB for the N
h
STS-48/STM-16 slice. When a logic 1 is written to SDLB[N], the ASSI add data of
STS-48/STM-16 slice N is looped back into the DSSI Drop data of STS-48/STM-16 slice
N. When a logic 0 is written to SDLB[N], the system diagnostic loopback is inactive.
Note: For the SDLB to function properly, the Add and Drop frame pulses must be aligned.
The easiest way to do this is to assert AFP_ON_DFP (reg 0001H), but it can also be done
by adjusting AFPDLY and/or DFPDLY (registers 001AH and 001BH).