
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
120
Normal operation occurs when the character alignment sub-block is in the SYNC state. 8B/10B
characters are extracted from the FIFO using the character alignment of the K28.5 character that
caused entry to the SYNC state. Mimic K28.5 characters at other alignments are ignored. The
receive data is constantly monitored for line code violations. If five or more LCVs are detected
in a window of 15 characters, the character alignment sub-block transitions to the HUNT state.
It will search all possible alignments in the receive data for the K28.5 character. In the
meantime, the original character alignment is maintained until a K28.5 character is found. At
that point, the character alignment is moved to this new location and the sub-block transitions to
the SYNC state.
14.19.4
Frame Alignment
The frame alignment sub-block monitors the data read from the FIFO buffer sub-block for the
J0 byte. When the frame counter sub-block indicates the J0 byte position, a J0 character is
expected to be read from the FIFO. If a J0 byte is read out of the FIFO at other byte positions, a
J0 byte error counter is incremented. When the counter reaches a count of 3, the frame
alignment sub-block transitions to HUNT state. The next time a J0 character is read from the
FIFO, the associated read address is latched and the sub-block transitions back to the SYNC
state. The J0 byte error counter is cleared when a J0 byte is read from the FIFO at the expected
position.
14.19.5
Character Decode
The character decode sub-block decodes the incoming 8B/10B control characters into an
extended set of TelecomBus control signals. Table 14 shows the mapping of 8B/10B control
characters into TelecomBus control signals. The table is divided into three sections, one for
each mode of operation in the 8B/10B encoder in an external device upstream of the
SPECTRA-9953 device. The character decoder sub-block itself is not mode-sensitive.
Table 14 Serial TelecomBus 8B/10B Character Decoding
Code
Group
Name
Curr. RD-
abcdei fghj
Curr. RD+
abcdei fghj
Decoded Signals
Description
Multiplex Section Termination (MST) Mode
K28.5
001111 0100
110000 1011
OJ0=’b1’
Transport frame alignment
OD[7:0] = ‘h01
K.28.4-
001111 0010
-
OPAIS=’b1’
High-order path AIS
OD[7:0] = ‘hFF
High-Order Path Termination (HPT) Mode
K28.0-
001111 0100
-
OPL = ‘b0,
High-order path H3 byte,
no negative justification event
OD[7:0] = ‘h00
K28.0+
-
110000 1011
OPL = ‘b0
High-order path PSO byte, positive
justification event