cx28365 Mindspeed Technologies, cx28365 Datasheet - Page 107

• Manufacturer Part Number: cx28365
• Description: X12, X6, X4 T3/e3 Framer And Atm Cell Transmission Convergence Sublayer Processor
• Manufacturer: Mindspeed Technologies

CX28365/6/4 Data Sheet
500028C
in loopback). Idle pattern and RAI transmission due to TxAlm bits are also valid
during this loopback.
When TxLOS bit in the Feature2 Control register is set, an all-0s signal is output on
the transmitter and overrides the content of the frame looped from the receiver.
This loopback is activated by setting PayldLp bit in the Feature3 Control register.
Framer Source Loopback
The source loopback loops the transmitter encoder outputs back to the system through
the receiver decoder inputs.
The transmitter data path is not affected by activation of this loopback and the
transmitted data is still present on the TxPOSO and TxNEGO pins. The transmitted
frame can be overwritten by an AIS pattern by setting TxAlm bits in the Mode Control
register to AIS control state. Doing this affects only TxPOSO and TxNEGO and not
the looped frame. Therefore, the AIS pattern is not looped by the transmitter. The
same behavior applies to TxLOS bit, i.e., when TxLOS is set during source loopback,
the TxPOSO and TxNEGO are forced to zero, and the looped frame is unaffected.
When an AIS or LOS pattern is generated, error insertion is invalid. Idle pattern and
RAI are not supported in this mode like AIS, i.e., they can overwrite the looped frame
by setting TxAlm bits as in normal operation.
Setting SourceLp bit in the Mode Control register activates this loopback.
NOTE:
NOTE:
Preliminary Information/Mindspeed Proprietary and Confidential
Mindspeed Technologies™
The transmitter does not generate an AIS or Idle pattern independently due to AIS or
Idle detection in the receiver during this loopback. The microprocessor must
program the transmitter to generate an AIS/Idle according to the receiver detection.
The shallow line loopback and source loopback cannot be operated simultaneously.
Functional Description
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