
MOTOROLA
Chapter 4. System Design Considerations
4-3
Repeater Mode
synchronization event marker. Ten-bit mode must be enabled for disparity based word
alignment to operate properly because it allows the improper disparity to pass through the
repeater. When Byte interface mode is enabled (TBIE set low) received data is passed
through the 8B/10B decoder where it is converted into its eight-bit data or control byte.
Running disparity and code validity are checked and reported with the received byte at the
receiver interface as described in
Section 3.3. The decoded byte is re-coded by the
transmitter’s 8B/10B encoder for transmission.
NOTE
Byte Interface mode must not be used with Non-Aligned mode.
4.3.2
Byte Alignment Mode
The Byte Alignment may be used in repeater mode as long as Ten-Bit Interface mode is not
also being used.
When establishing byte alignment for the link through the repeater, the byte alignment
sequence must be repeated twice, once for the repeater and once for the destination’s
receiver. For example, at least eight Idle characters must be transmit, four for repeater
alignment and four for the destination’s receiver alignment.
4.3.3
Word Synchronization Mode
Word synchronization may be used in Repeater mode. This allows the incoming bytes to be
synchronized into their corresponding words, removing cable skew from the transmission
source and re-establishing synchronization.
Similar to Byte Alignment, the Word Synchronization sequence must be repeated twice,
once for the repeater and once for destination’s receiver. For example, a 4 Idle/1 non-Idle
word synchronization event must be transmit followed by a second 4 Idle/1 non-Idle word
synchronization event to enable the entire link to establish word synchronization. Of
course, byte alignment must be established, as described in
Section 4.3.2, prior to word
synchronization.
4.3.4
Recovered Clock Timing Mode
The MC92610’s four transmitters are timed exclusively to the Reference Clock domain.
Recovered Clock mode cannot be used in Repeater mode. The setting on the Recovered
Clock Enable input, RCCE, is ignored when in Repeater mode and all data is timed to the
Reference Clock.
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Freescale Semiconductor, Inc.
For More Information On This Product,
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