
XRT7250
DS3/E3 FRAMER IC
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REV. 1.1.1
170
NOTE: This bit is ignored when either the Transmit Yellow
Alarm, Tx AIS, Tx IDLE, or TxLOS bit is set.
4.2.4.2.1.3
Transmit Idle Pattern - Bit 5
This read/write bit field permits the user to transmit an
Idle pattern to the remote terminal equipment upon
software control.
Table 29 relates the contents of this
bit field to the Transmit DS3 Framer's action.
NOTE: This bit is ignored when either the Tx AIS or the Tx
LOS bit is set.
4.2.4.2.1.4
Transmit AIS Pattern - Bit 4
This read/write bit field allows the user to transmit an
AIS pattern to the remote terminal equipment, upon
software control.
Table 30 relates the contents of this
bit field to the Transmit DS3 Framer block's action.
TABLE 28: THE RELATIONSHIP BETWEEN THE CONTENTS OF BIT 6 (TX X-BITS) WITHIN THE TX DS3 CONFIGURATION
REGISTER, AND THE RESULTING TRANSMIT DS3 FRAMER BLOCK'S ACTION
BIT 6TRANSMIT DS3 FRAMER'S ACTION
0
Normal Operation:
The X-bits are generated by the Transmit DS3 Framer block based upon Receiving Conditions (as detected
by the Receive Section of the Framer chip).
1
Set X-bits to 1:
The Transmit DS3 Framer will overwrite the X-bits by setting them to 1. Payload information is not modified
and is transmitted as normal.
TABLE 29: THE RELATIONSHIP BETWEEN THE CONTENTS OF BIT 5 (TX IDLE) WITHIN THE TX DS3 CONFIGURATION
REGISTER, AND THE RESULTING TRANSMIT DS3 FRAMER ACTION
BIT 5TRANSMIT DS3 FRAMER'S ACTION
0
Normal Operation:
The Overhead bits are either internally generated, or they are inserted via the Transmit Overhead Data Input
Interface or the Transmit HDLC Controller blocks. The Payload bits are received from the Transmit Payload Data
Input Interface.
1
Transmit Idle Condition Pattern:
When this command is invoked, the Transmit DS3 Framer will do the following:
Set the X-bits to 1
Set the CP-Bits (F-Frame #3) to 0
Generate Valid M, F, and P bits
Overwrite the data in the DS3 payload with a repeating 1100... pattern.