Instruction Manual

DS26503 T1/E1/J1 BITS Element
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11. T1 SYNCHRONIZATION STATUS MESSAGE
The DS26503 has a BOC controller to handle SSM services in T1 mode.
Table 11-1. T1 SSM Messages
QUALITY
LEVEL
DESCRIPTION BOC CODE
1 Stratum 1 Traceable 0000010011111111
2 Synchronized Traceablity Unknown 0000100011111111
3 Stratum 2 Traceable 0000110011111111
4 Stratum 3 Traceable 0001000011111111
5 SONET Minimum Clock Traceable 0010001011111111
6 Stratum 4 Traceable 0010100011111111
7 Do Not Use For Synchronization 0011000011111111
User Assignable Reserved For Network Synchronization Use 0100000011111111
11.1 T1 Bit-Oriented Code (BOC) Controller
The DS26503 contains a BOC generator on the transmit side and a BOC detector on the receive side. The
BOC function is available only in T1 mode. In typical BITS applications, the BOC controller would be
used to transmit and receive Synchronization Status Messages in T1 mode over the data link.
11.2 Transmit BOC
Bits 0 through 5 in the TFDL register contain the BOC or synchronization status message to be
transmitted. Setting BOCC.0 = 1 causes the transmit BOC controller to immediately begin inserting the
BOC sequence into the FDL bit position. The transmit BOC controller automatically provides the abort
sequence. BOC messages will be transmitted as long as BOCC.0 is set. TFSE (T1TCR2.6) must be set =
0 when using the transmit BOC function.
To transmit a BOC, use the following:
1) Write 6-bit code into the TFDL register.
2) Set SBOC bit in BOCC register = 1.