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Out of frame (oof) monitoring, Data transfer – Maxim Integrated DS33Z41 User Manual

Page 36

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DS33Z41 Quad IMUX Ethernet Mapper

36 of 167

8.9.3 Out of Frame (OOF) Monitoring

Once the links are in synchronization, frame synchronization monitoring is started. The device will declare an out
of frame (OOF) if 2 consecutive sequence errors are received. The device automatically adjusts for single-frame
slips by increasing or decreasing the expected frame sequence number. If a frame sequence number is neither
repeated nor skipped by one (indicating a single-frame slip), it is considered a sequence error. Two consecutive
frames with sequence errors result in an OOF state being declared. The OOF state is used to set OOF Latched
bits in

GL.IMXOOFLS

and an OOF command is sent to the distant end. If an OOF command is received from the

distant end, the latched status register will be updated.

8.9.4 Data

Transfer

Once synchronization is established, data transfer is enabled by the microprocessor setting the

GL.IMXCN

.RXE

and

GL.IMXCN

.SENDE bits. The user must then reset the queue pointers (

GL.C1QPR

) for proper data transfer.

Data is byte-striped across the available links.