tfra08c13 ETC-unknow, tfra08c13 Datasheet - Page 95

• Manufacturer Part Number: tfra08c13
• Description: Tfra08c13 Octal T1/e1 Framer
• Manufacturer: ETC-unknow

Preliminary Data Sheet
October 2000
Lucent Technologies Inc.
Lucent Technologies Inc.
Facility Data Link
Diagnostic Modes
Loopbacks
The serial link interface can operate in two diagnostic loopback modes: (1) local loopback and (2) remote loopback.
The local loopback mode is selected when register FDL_PR1 bit 1 (FLLB) is set to 1. The remote loopback is
selected when register FDL_PR1 bit 0 (FRLB) is set to 1. For normal traffic, i.e., to operate the transmitter and
receiver independently, the FLLP bit and the FRLB bits should both be cleared to 0. Local and remote loopbacks
cannot be enabled simultaneously.
In the local loopback mode:
In the remote loopback mode:
The transmitter should be disabled. The receiver can be disabled or, if desired, enabled. Received data is sent as
usual to the receive FIFO if the receiver is enabled
TFDLCK clocks both the transmitter and the receiver.
The transmitter and receiver must both be enabled.
The transmitter output is internally connected to the receiver input.
The TFDL is active.
The RFDL input is ignored.
The communication between the transmit and receive FIFO buffers and the microprocessor continues normally.
Transmitted data is retimed with a maximum delay of 2 bits.
Received data is retransmitted on the TFDL.
XMIT HDLC FDL BLOCK
RCVR HDLC FDL BLOCK
RCVR FIFO
XMIT FIFO
(continued)
RCVR HDLC
XMIT HDLC
Figure 34. Local Loopback Mode
INTERFACE
INTERFACE
FDL RCVR
FDL XMIT
TFRA08C13 OCTAL T1/E1 Framer
TFDL
RFDL
TFDLCK
RFDLCK
5-4562(F)r.2
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