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DS34S132 DATA SHEET
19-4750; Rev 1; 07/11
37 of 194
9.2.2.2 TDM Port Receive Interface
The T1/E1 Receive interface is controlled using the Pn.PRCR1 and Pn.PRCR2 registers to program the following
functions (more of the PRCR1 functions are described in the sub-sections that follow):
RSTS:
Select the receive framing to be synchronized to RSYNCn or internal transmit framing
RDS:
Select RSYNCn direction to be input or output
RIES:
Select RDATn, RSIGn and RSYNCn timed to the positive or negative RCLKn edge
RSS:
Select clock source to be RCLKn or TCLKOn
CS:
Select RDAT or RSIG for TXP direction CAS Signaling interface
9.2.3 TDM Port Structure & Frame Formats
The TDM Ports support the Structured (with Framing) and Unstructured (without Framing) Formats. The Structured
Format is used by T1/E1 CES applications. The Unstructured Format is used by T1/E1 SAT and non-T1/E1 SAT
applications. The SAT/CES Format for each TDM Port is programmed using Pn.PTCR1.SFS and Pn.PRCR1.SFS.
The programmed SAT/CES Format for all RXP and TXP Bundles (B.BCDR4.RXBTS and B.BCDR3.TXBTS) must
be the same as the programmed SAT/CES Format for the TDM Port that they are assigned to.
The Structured Format (CES) is programmed to T1 or E1 Framing using Pn.PRCR1.FFS and Pn.PTCR1.FFS. The
Multi-frame formats that are supported in the Structured Format (CES) are: no multi-frame, T1 SF, T1 ESF and E1
(selected using Pn.PRCR1.MFS and Pn.PTCR1.MFS). For CES with MFS = “no multi-frame” the RSYNC/TSYNC
pulse period is ~125 us (“193 bits/frame” for T1 or “256 bits/frame” period for E1) and CAS is not supported. For the
remaining CES settings the RSYNC/TSYNC periods are based on a “12 x 193 bit”, “24 x 193 bit” or “16 x 256 bit”
period (for SF, ESF or E1 respectively) and CAS Signaling is included.
SFS and MFS should be set to be the same as that of the “l(fā)ocal” external transceiver (e.g. T1/E1 Framer). The
MFS setting is a multi-frame setting to enable the CAS functions of the S132. The MFS setting may differ from the
external transceiver where the multi-frame format setting determines both the T1/E1 framing pattern and the CAS
Signaling format. For multi-frame, non-CAS applications the S132 MFS should be set for MFS = “no multi-frame”
(meaning no CAS multi-frame) and the external transceiver should be set to T1-SF, T1-ESF or E1. This will disable
the S132 CAS Signaling functions and the frame synchronization will only be used to frame align the Timeslots.
In most applications the T1/E1 format at both ends of a PW are the same (e.g. T1 SF to T1 SF). Some unusual T1
CAS applications may prefer to translate one T1 CAS format to the other (e.g. translate T1 SF CAS to T1 ESF
CAS). This function is a unidirectional S132 function that is implemented in the TXP direction using the TXP Bundle
Payload Multi-frame Format setting (B.BCDR1.SCTXDFSE; the RXP direction does not support translation). The
SCTXDFSE setting should always match the T1 CAS Format of the far end T1 PW termination end point (this
setting is not used for E1 and T1 non-CAS applications). For T1 CAS applications the SCTXDFSE setting can differ
from the MFS settings to provide a T1 CAS Multi-frame Format translation (or be the same for no translation). An
example T1 ESF CAS to SF CAS Translation is depicted in
Figure 9-12. More CAS translation information is
provided in the “TDM CAS to Packet CAS Translation” section.
Figure 9-12. T1 ESF CAS to SF CAS Translation Example
S132
T1
/E
1
Framer
RXP
Bundle
TXP
Bundle
TDM
Xmt
Port
TDM
Rcv
Port
S132
T1
/E
1
Framer
RXP
Bundle
TXP
Bundle
TDM
Xmt
Port
TDM
Rcv
Port
T1
ESF
T1
SF
SCTXDFSE = SF
PRCR1.FFS & MFS = ESF
PTCR1.FFS & MFS = ESF
SCTXDFSE = SF
PRCR1.FFS & MFS = ESF
PTCR1.FFS & MFS = ESF
TXP
Direction
TXP
Direction
RXP
Direction
RXP
Direction
PSN
Internally, the data for SAT/CES Bundles is processed using data that is stored in short term, Staging Buffers. The
buffers are filled and then forwarded. Each Staging Buffer is divided into fragments (blocks) of data. One Fragment
stores the SAT/CES data for a 125 us period (TDAT or RDAT data). Pn.PRCR1.BPF and Pn.PTCR1.BPF specify