cx28365 Mindspeed Technologies, cx28365 Datasheet - Page 74

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

Functional Description
2-36
In the presence of LOS in the E3 and DS3 modes, if the Auto RAI field is set in the
Transmit Overhead Insertion 1 Control register, RAI/RDI is transmitted on the
transmit stream.
In the presence of LOS in the E3 and DS3 modes, if the RxAutoAll1 field is set in the
Feature5 Control register, an all-1s sequence is transmitted on RxDATO towards the
receive system side.
Framing Bit Error (FBE)
In E3, an FBE event occurs when a framing bit (FAS, F, M, or FA) in the receive
stream is different from the expected value. The FBE event increments a FBE counter.
In DS3 C-bit parity mode, an FBE event is valid and counted. If internal FEBE
generation is programmed for the transmitter by clearing the ExtFEBE/Cj-bit in the
TransmitOverheadInsertion1 Control register, the detection of a framing bit error in
the receiver causes transmission of FEBE error code by the transmitter.
Out of Frame (OOF)
In DS3 mode, an OOF event is declared if, in the receive data stream, there are three
or more F-bit framing bit errors in sixteen consecutive F-bits or one or more M-bit
FBEs per frame in two or more of four consecutive frames. The OOF is terminated
upon the non-occurrence of FBEs in three consecutive frames. The checking of F-bits
is done in batches of 16 F-bits and not as a sliding window.
In E3-G.751 mode, an OOF event is declared if, in the receive data stream, there is
one or more FBEs per frame in four consecutive frames. The OOF is terminated if
there are no FBEs in three consecutive frames.
In E3-G.832 mode, an OOF event is declared if, in the receive data stream, there is
one or more FBEs per frame in four consecutive frames. An OOF event is also
declared if there are PER in 986 or more frames in a block of 1000 frames. The OOF
is terminated if there are no FBEs in three consecutive frames.
The OOF event generates an OOFStrt interrupt indication and sets the OOF status
indication bit in the OOFAlm field of the Maintenance Status register. Terminating the
OOF event generates an OOFEnd Interrupt and clears the OOF status indication bit.
In E3 mode, in the presence of OOF, RAI/RDI is transmitted on the transmit stream if
the AutoRAI field in the TransmitOverheadInsertion 1 Control register is set.
In both E3 and DS3 modes, in the presence of OOF, an all-1s sequence is transmitted
on the RxDATO toward the receive system side if the RxAutoAll1 field in Feature5
Control register is set.
Severely Errored Frame (SEF)
In DS3, an SEF event is declared when there are three or more F-bit FBEs in sixteen
consecutive F-bits. This is terminated when the framer is in frame (i.e., OOF end).
This is not specified in E3 mode.
The SEF event generates a SEFStrt interrupt indication. Because the termination
criteria for SEF is identical to OOF, there is no SEF-end interrupt indication.
NOTE:
Preliminary Information/Mindspeed Proprietary and Confidential
Mindspeed Technologies™
While the framer is searching for a new framing template, the old one is maintained
for ongoing performance monitoring (e.g., FBE) and output signaling (e.g., RxSync).
CX28365/6/4 Data Sheet
500028C