Anyone know the difference between LVDS_25 and BLVDS_25 in Xilinx's Virtex II Pro or point me to a spec. where I can read about the electrical characteristics of these two? Searching through Xilinx.com has yielded zero. [When I set IOSTANDARD=BLVDS_25 for some of my differential (OBUFDS) outputs, I get an Exception during mapping in Xilinx's ISE 6.1.03i. LVDS_25 works fine for all my differential I/O, so I'm wondering whether I can get away with using LVDS_25 instead.] -- ����`����,,,,����`����,,,,����`����,,,,����`�������`����,,,,��� eNo ����`����,,,,����`����,,,,����`����,,,,����`�������`����,,,,���
Xilinx Virtex II Pro: LVDS_25 vs. BLVDS_25
Started by ●February 2, 2004
Reply by ●February 3, 20042004-02-03
eNo, LVDS is a standard differential interface covered by ANSI/IEEE. "Bus LVDS" is a non-standard for a multi-drop differential interface. It is accomplished in the IOBs by using a tristate-able standard LVCMOS IO, and its complement, and two external resistors whose value is chosen by the number of transmitters and receivers on the bus. It is covered in the User's Guide, under the IOs. Austin eNo wrote:> Anyone know the difference between LVDS_25 and BLVDS_25 in Xilinx's Virtex > II Pro or point me to a spec. where I can read about the electrical > characteristics of these two? Searching through Xilinx.com has yielded zero. > [When I set IOSTANDARD=BLVDS_25 for some of my differential (OBUFDS) > outputs, I get an Exception during mapping in Xilinx's ISE 6.1.03i. LVDS_25 > works fine for all my differential I/O, so I'm wondering whether I can get > away with using LVDS_25 instead.] > > -- > ����`����,,,,����`����,,,,����`����,,,,����`�������`����,,,,��� > eNo > ����`����,,,,����`����,,,,����`����,,,,����`�������`����,,,,��� > >
