Xilinx Virtex-5 RocketIO GTP User Manual

180 www.xilinx.com Virtex-5 RocketIO GTP Transceiver User Guide
UG196 (v1.3) May 25, 2007
Chapter 7: GTP Receiver (RX)
R
To set up a daisy chain, first connect the GTP transceivers using RXCHBONDO and
RXCHBONDI to create a path from the RXCHBONDI port of each slave to the
RXCHBONDO port of the master. Use the following steps to set the
CHAN_BOND_LEVEL for the GTP transceivers in the chain:
1. Set the CHAN_BOND_LEVEL of the master to 7.
2. Set the CHAN_BOND_LEVEL of each slave to the CHAN_BOND_LEVEL of the GTP
transceiver driving the slave’s RXCHBONDI port minus 1.
3. Find the slave with the lowest level. Subtract this level from the
CHAN_BOND_LEVEL of all of the GTP transceivers so that the lowest slave has
level 0 and the master has the minimum level required to service all the slaves.
Setting the Channel Bonding Sequence
The channel bonding sequence is programmed in the same way as the clock correction
sequence. CHAN_BOND_SEQ_LEN sets the length of the sequence from one to four
subsequences. CHAN_BOND_SEQ_1_* sets the values of the sequence. If
CHAN_BOND_SEQ_2_USE is TRUE, CHAN_BOND_SEQ_2_* sets the values for the
alternate second sequence.
The number of active bits in each subsequence depends on INTDATAWIDTH (see
Chapter 5, “Tile Features”) and RX_DECODE_SEQ_MATCH (see “Configurable Clock
Correction,” page 168). Figure 7-31 shows how the subsequence bits are mapped.
As with clock correction sequences, channel bonding sequences can have don't care
subsequences. CHAN_BOND_SEQ_1_ENABLE and CHAN_BOND_SEQ_2_ENABLE set
these bytes. Figure 7-32 shows the mapping of the enable attributes for the channel
bonding subsequences.
Figure 7-31: Channel Bonding Sequence Settings
Figure 7-32: Channel Bonding Sequence Mapping
8-Bit Channel Bonding Sequence
1 = Sequence is a K Character
0 = Sequence is Regular Character
1 = Sequence Uses Inverted Disparity
0 = Sequence Uses Regular Disparity
7:0
UG196_c7_28_092606
89CHAN BOND_SEQ_x_y
UG196_c7_29_092606
3412
CHAN_BOND_SEQ_x_4 CHAN_BOND_SEQ_x_3 CHAN_BOND_SEQ_x_2
CHAN_BOND_SEQ_x_ENABLE
CHAN_BOND_SEQ_x_1

Xilinx Virtex-5 RocketIO GTP Specifications

General

Brand	Xilinx
Model	Virtex-5 RocketIO GTP
Category	Transceiver
Language	English