3.0 Registers
CX28394/28395/28398
3.14 Bit-Oriented Protocol Registers
Quad/x16/Octal—T1/E1/J1 Framers
RBOP_LEN[1:0]
RBOP Message Length—Selects the number of successive identical 16-bit patterns that are
needed to qualify receipt of a single BOP message and to update RBOP [addr 0A2] with the
received codeword. At this time RBOP interrupt [ISR1; addr 00A] is also activated. Successive
patterns can be separated by any number of bits as long as they do not contain a different valid
codeword.
RBOP_LEN
Successive Patterns
Notes
00
01
10
11
1
10
Single 16-bit pattern updates RBOP
Minimum command, response length
Preferred command, response length
RBOP updates on receipt of each new pattern
25
Change
TBOP_LEN[1:0]
TBOP Message Length—Selects the number of repeated 16-bit patterns sent as a single
message when a TBOP [addr 0A1] codeword is written. Another message, with the same or
different codeword value, can be written to TBOP as soon as prior message start is
acknowledged via activation of TBOP interrupt [ISR2; addr 009]. If no new message is
written, the FDL channel returns to TDL1 output control upon completion of message
transmission. Processor changes TBOP_LEN to end transmission of a continuously repeating
message.
TBOP_LEN
Repeated
Patterns
Message
Length (ms)
Notes
00
01
10
11
1
10
4
40
Single message sends 16 FDL bits
Minimum command, response length
Preferred command
25
100
Continuous
Continuous
Required for ESF yellow alarm
TBOP_MODE[1:0] Transmit BOP Mode—Enables BOP transmitter and establishes priority of TBOP [addr 0A1]
output in relation to TDL1 [addr 0AD] output. When TBOP messages are given output
priority, any write to TBOP aborts TDL1 output within the next eight FDL bit times and then
suspends TDL1 data output until TBOP has completed transmission. The processor can check
TMSG1 status [addr 0AE] before writing TBOP to determine if TDL1 output is idle. TDL1
buffer can be written while TBOP is granted priority.
When TDL1 messages are given output priority, TBOP output is suspended when the TDL1
buffer becomes non-empty. Furthermore, TBOP is forced to wait until the TDL1 buffer is
empty and the TDL1 output is in the idle state. If TBOP_LEN is continuous and TDL1/PRM
message output is pending, then TBOP will be suspended at the next 16-bit pattern boundary.
TDL1 priority is used to transmit PRM, DS1 Idle (ISID), or optional path maintenance (PID,
TSID) messages separated by ESF Yellow Alarm codewords as defined in Annex D of ANSI
T1.403.
TBOP_MODE
Mode Description
Disabled: TBOP writes are ignored
0X
10
11
TBOP output priority
TDL1 output priority
3-72
Conexant
100054E
CONEXANT [ CONEXANT SYSTEMS, INC ]
