Serialization; Defining Clock Correction And Channel Bonding Sequences; Rxstatus Bus; Pre-Emphasis, Differential Swing, And Equalization - Xilinx Virtex-5 RocketIO GTP User Manual

Appendix A: MGT to GTP Transceiver Design Migration

Serialization

As in Virtex-4 devices, Virtex-5 GTP transceivers serialize and send the least significant
byte first. Virtex-II Pro devices send the most significant byte first.

Defining Clock Correction and Channel Bonding Sequences

The bit definitions of the CLK_COR_SEQ and CHAN_BOND_SEQ have changed to
support more encoding functionality.
Table A-11: CLK_COR_SEQ and CHAN_BOND_SEQ Sequences
Bit Definition
8B/10B encoded definition
10-bit literal value
64B/66B encoding (sync character)
8-bit literal value (for 64B/66B and other encodings)
Notes:
1. Defines K28.5.
2. Defines K28.5 and depends on CLK_COR_8B10B_DE (plus all 10 bits are defined).

RXSTATUS Bus

Several buses have changed over the FPGA generations to improve the information that is
indicated.
Table A-12: Status Bus Changes
Description
Indicates channel bonding complete
Indicates status bus is status, data, event
Indicates channel bonding or clock correction
pointers change
Indicates that an RX buffer has
underflow/overflow
Notes:
1. Signal optimization settings are independent between both GTP transceivers of a GTP_DUAL tile. GTP0 is indicated by the suffix
"0" after the signal name, and GTP1 is indicated by the suffix "1" (for example, RXENEQB0 or RXENEQB1).
2. RXCLKCORCNT must go to 3'b101 before channel bonding is complete.

Pre-emphasis, Differential Swing, and Equalization

The differential signaling techniques are more robust in recent Xilinx transceivers. The
Virtex-5 GTP transceiver adds ports to control TX characteristics to simplify
reconfiguration.
Virtex-4 MGTs to Virtex-5 GTP transceivers.
264
Virtex-II Pro
MGT
00110111100
10011111010
N/A
N/A
Table A-12 shows the migration from Virtex-II Pro to Virtex-5 devices.
Virtex-II Pro
MGT
CHBONDONE
N/A
RXCLKCORCNT
RXBUFSTATUS[1]
Table A-13 shows the migration of attributes from Virtex-II Pro and
www.xilinx.com
Table A-11 illustrates the differences.
Virtex-4
MGT
(1)
00110111100
(1)
10011111010
1XX (sync header)
1XX (8-bit data)
Virtex-4
MGT
(2)
RXSTATUS[5]
RXSTATUS[4:3]
RXSTATUS[2:0]
RXBUFERR
Virtex-5 RocketIO GTP Transceiver User Guide
Virtex-5 GTP
Transceiver
(2)
(2)
N/A
N/A
Virtex-5 GTP
(1)
Transceiver
RXCHANISALIGNED
RXSTATUS[2:0]
RXCHANREALIGN
RXBUFSTATUS[2:0]
UG196 (v1.3) May 25, 2007
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