Ports And Attributes; Chan_Bond_Mode; Enchansync; Chan_Bond_One_Shot - Xilinx RocketIO User Manual

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Channel Bonding (Channel Alignment)
Table 2-19
in Master and Slave applications.
Table 2-19: Master/Slave Channel Bonding Attribute Settings

CHAN_BOND_ONE_SHOT

ENCHANSYNC

Ports and Attributes

CHAN_BOND_MODE

An MGT can be designated as one of three types when used in a channel-bonding scheme.
The type is designated by CHAN_BOND_MODE, the three values of which are MASTER,
SLAVE_1_HOP, and SLAVE_2_HOPS. (A fourth mode, OFF, is used when channel
bonding is not being performed.) The Master always controls, for itself and for Slaves of
either type, when channel bonding and clock correction will occur.
Masters are always connected directly to a SLAVE_1_HOP, and indirectly to a
SLAVE_2_HOPS via daisy-chain through a SLAVE_1_HOP. This topology improves the
timing characteristics of the CHBONDO and CHBONDI buses.
ENCHANSYNC
ENCHANSYNC controls when channel bonding is enabled.
recommended settings for Master and Slaves. To counter the possibility of a bit error
causing a false channel bonding sequence to occur, this port is usually de-asserted once a
group of channels have been successfully aligned.
CHAN_BOND_ONE_SHOT
As with ENCHANSYNC, many applications will require that the channels be aligned only
once. CHAN_BOND_ONE_SHOT = TRUE allows the Master to initiate a channel bonding
only once. This remains true even if more channel bonding sequences are received. (The
channels may be aligned again if RXRESET is asserted and then deasserted, and
ENCHANSYNC is deasserted and then reasserted.)
CHAN_BOND_ONE_SHOT may be set to FALSE when very few channel bonding
sequences appear in the data stream. (For Slave instantiations, this attribute should always
be set to FALSE. See
in the data stream, however, it is recommended that this attribute be set to TRUE in order
to prevent the RX buffer from over- or underflowing.

CHAN_BOND_SEQ_ * _ * ,

CHAN_BOND__SEQ_LEN,

CHAN_BOND_SEQ_2_USE

The channel bonding sequence (CBS) is similar in format to the clock correction sequence. The
CBS is set to the appropriate sequence for the primitives supporting channel bonding.
GT_CUSTOM is the only primitive allowing modification to the sequence. These
sequences are comprised of one or two sequences of length up to 4 bytes each, as set by
CHAN_BOND_SEQ_LEN and CHAN_BOND_SEQ_2_USE.
RocketIO™ Transceiver User Guide
UG024 (v3.0) February 22, 2007
shows different settings for CHAN_BOND_ONE_SHOT and ENCHANSYNC
Table 2-19.) When the channel bonding sequence appears frequently
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Master
TRUE or FALSE as desired
Dynamic control as desired
Table 2-19
R
Slave
FALSE
Tie High
shows the
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