Xilinx Virtex-5 RocketIO GTP User Manual

154 www.xilinx.com Virtex-5 RocketIO GTP Transceiver User Guide
UG196 (v1.3) May 25, 2007
Chapter 7: GTP Receiver (RX)
R
Manual Alignment
RXSLIDE can be used to override the automatic comma alignment and to shift the parallel
data. RXSLIDE is driven High for one RXUSRCLK2 cycle to shift the parallel data to the left
by one bit. RXSLIDE must be Low for at least two RXUSRCLK2 cycles before it can be used
again.
Figure 7-16 shows the waveforms for manual alignment using RXSLIDE, before and after
the data shift.
Figure 7-15: Comma Alignment Boundaries
RXDATAWIDTH
0 (1-byte)
0 (1-byte)
1 (2-byte)
1 (2-byte)
ALIGN_COMMA_WORD
1 (Any Boundary)
2 (Even Boundary Only)
1 (Any Boundary)
UG196_c7_15_092606
2 (Even Boundaries Only)
Possible RX Alignments
(Grey = Comma Can Appear
on Byte)
RXDATA Byte 0
Invalid Configuration
RXDATA Byte 1 RXDATA Byte 0
RXDATA Byte 1 RXDATA Byte 0
Figure 7-16: Manual Data Alignment Using RXSLIDE
RXUSRCLK2
RXSLIDE
RXDATA
TXDATA
0000010000
0000010000
0001000000
0000100000
UG196_c7_16_092606
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
Slide Results on RXDATA
After Several Cycles of Latency
Notes:
1. Latency between the slide and the slide result at RXDATA depends on the number of active RX PCS blocks in the datapath.

Xilinx Virtex-5 RocketIO GTP Specifications

General

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