VSC6134
Datasheet
Table 23. ADD/DROP_TCMCTRL[1:0] Decoding (continued)
ADD/DROP_TCMCTRL[1:0]
Function
11
The following actions are taken for the TCMi pointed to by
ADD/DROP_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 FPGA1in 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 sourced from the FPGA
TCMi BEI count is sourced from the FPGA.
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 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.
1. In the non-FPGA mode, zeros are inserted for the reserved bytes.
ADD/DROP_OTU_TCM[12:7] bits in Table 161, page 260 define which of the six TCM fields are
modified or passed through. This is programmable in any combination of six (that is, none, some, all).
ADD/DROP_TCM_TTI[31:0][15:0] is implemented as a stack and is accessible through a single
microprocessor address. The pointer ADD/DROP_TCM_TTI_PNT[5:0] points to the
ADD/DROP_TCM_TTI[15:0] location that is written to or read from the stack by the next
microprocessor write or read to ADD/DROP_TCM_TTI[15:0].
ADD/DROP_TCM_TTI_PNT[5:0] can be written to or read by the microprocessor.
ADD/DROP_TCM_TTI_PNT[5:0] is incremented automatically after each access to
ADD/DROP_TCM_TTI[15:0].
2.7.5.6
TCM Activation/Deactivation Coordination (TCM ACT)
The operation of the TCM ACT byte generator is controlled by ADD/DROP_TP_RES. Decoding for
ADD/DROP_TP_RES is shown in the following table.
Table 24. ADD/DROP_TP_RES Decoding for TCM ACT
ADD_TP_RES
Function
0
1
The TCM ACT byte is sourced from the FPGA.(1)
The TCM ACT byte is sourced from the received data in the OTUk to FEC or FEC
loopback modes, respectively.
1. In the non-FPGA mode, zeros are inserted for the reserved bytes.
91 of 438
VMDS-10185 Revision 4.0
July 2006
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
