VSC6134
Datasheet
The update of the ODUk TCM subfields is controlled (enabled and disabled) using the microprocessor
programmable bits ADD/DROP_TCMCTRL[1:0]. The decoding for ADD/DROP_TCMCTRL[1:0] is
shown in the following table.
Table 23. ADD/DROP_TCMCTRL[1:0] Decoding
ADD/DROP_TCMCTRL[1:0]
Function
00
The following actions are taken for the TCMi pointed to by
ADD/DROP_OTU_TCM[2:0]. All other TCM locations are sourced from the
received data in the OTUk to FEC or FEC loopback modes, or are sourced from
the FPGA1 in SONET/SDH mode.
TCMi TTI bytes are sourced from a 32 × 16-bit array, TCM_TTI[31:0][15:0], and
inserted in 64 consecutive frames, aligned with the MFAS.
TCMi BIP-8 is computed over the bits in the OPUk columns of OTUk frame i and
is inserted in OTUk frame i + 2.
TCMi BDI bit is set on the add side when there is a drop signal fail condition on
the drop path and on the drop side when there is an add signal fail condition on
the add path. Drop signal fail (DSF) and add signal fail (ASF) are declared when
either an LOS or LOF or both are detected. SF is programmed by the
OTU_BDISF[1:0] bits.
TCMi BEI count is sourced from the OTUk overhead monitor block.
TCMi STAT is sourced from the microprocessor accessible register
TCM_STAT[2:0] in the absence of IAE. This register has a default value of 001.
TCMi STAT bits are automatically set to 010 to indicate a frame alignment error
(IAE) when AUTO_TCMIAE = 1. The TCMi IAE is asserted for 16 multiframes
when the OTUk frame aligner (OTUk to FEC mode) or the drop FEC frame aligner
(FEC regenerator mode) has entered the OOF state. IAE is asserted for 16
multiframes on each assertion of OTU_OOF or FEC_OOF. Each new declaration
of IAE restarts the 16 multiframe insertion counter. IAE can be declared at any
time through the microprocessor by a 0 to 1 transition on microprocessor
programmable bit TCM_IAE. Each 0 to1 transition causes IAE to be asserted for
16 multiframes.
01
10
The following actions are taken for the TCMi pointed to by ADD_OTU_TCM[2:0].
All other TCMi locations are sourced from the received data in the OTUk to FEC
or FEC loopback mode, or are sourced from the FPGA1 in SONET/SDH mode.
All TCMi subfields, except for TCM BIP-8, are sourced from the FPGA1.
TCMi BIP-8 is computed over the bits in the OPUk columns of OTUk frame i and
is inserted in OTUk frame i + 2.
All TCMi subfields are sourced from the received DWOH data.
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VMDS-10185 Revision 4.0
July 2006
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
