Blvds (Bus Lvds) - Xilinx SelectIO 7 Series User Manual

Chapter 1: SelectIO Resources

BLVDS (Bus LVDS)

Table 1-53: Available I/O Bank Type
Since LVDS is intended for point-to-point applications, BLVDS is not an EIA/TIA standard
implementation and requires careful adaptation of I/O and PCB layout design rules. The
primitive supplied in the software library for bidirectional LVDS does not use the 7 series
FPGA LVDS current-mode driver, instead, it uses complementary single-ended differential
drivers. Therefore, source termination is required. BLVDS is only available in HR I/O
banks and requires a V
Table 1-54
Table 1-54: Allowed Attributes of the BLVDS I/O Standard
IOSTANDARD
Figure 1-73
X-Ref Target - Figure 1-73
96
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HR HP
Available N/A
voltage level of 2.5V. The IOSTANDARD is called BLVDS_25.
CCO
summarizes all the possible BLVDS I/O standards.
Attributes
IBUFDS_DIFF_OUT, or
IBUFGDS_DIFF_OUT
shows the BLVDS transmitter termination.
BLVDS_25 IOB
R
165Ω
BLVDS_25
R
165Ω
Figure 1-73: BLVDS Transmitter Termination
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Primitives
IBUFDS, IBUFGDS,
BLVDS _25
Z 0 = 50Ω
S
R DIV
R DIFF = 100Ω
140Ω
Z 0 = 50Ω
S
7 Series FPGAs SelectIO Resources User Guide
OBUFDS, OBUFTDS, IOBUFDS,
or IOBUFDS_DIFF_OUT
IOB
IN
BLVDS_25
-
+
INX
ug471_c1_62_011811
UG471 (v1.10) May 8, 2018
Data in