ʱ : һ FPGA的LVDS介绍和xilinx原语的使用方法中文说?- 百度文库ϿʼĶ
Ҫdiv2_diff.schйܽԼdiv2_diff.ucfԼļ£ NET \ LOC = \ | IOSTANDARD = LVDS_25 ; NET \ LOC = \ | IOSTANDARD = LVDS_25 ;
NET \ LOC = \ | IOSTANDARD = LVCMOS33 ; NET \ LOC = \ | IOSTANDARD = LVCMOS33 ;
Ҫע⣺
clk_nclk_pҪڲֹܽŶϣ clk_nC9IO_L14P clk_pD9IO_L14N
ƽΪLVDS_25Spartan-3E֧IJƽ ? LVDS
? Bus LVDS
? mini-LVDS ? RSDS
? Differential HSTL (1.8V, Types I and III) ? Differential SSTL (2.5V and 1.8V, Type I) ? 2.5V LVPECL inputs
ۺϡ롢ӳͲֺ߲вַ߲棬ԿʱclkѾΪʱˡ
div2_diff.schHDLļView HDL Functional ModelԿʵschIBUFGDSԭ
ڲУΪôʹۺϳĴ£
ERROR:Place:332 - This design contains an LVDS IO pair. The pair of IOs must be placed in a specific relative structure.
The two IOs can not be placed in this specific structure. The reason for this issue:
All of the logic associated with this structure is locked and the relative placement of the logic violates the
structure. The problem was found between the relative placement of IBUF clk_p at site PAD27 and IBUF clk_n at site
IPAD28. The following components are part of this structure: IBUF clk_p IBUF clk_n
Ϊֹܽclk_pclk_nûԼоƬIJֶԹܽϡҪ.ucfļоƬĸܽDzֶԣԲοӦоƬ
DatasheetXC3S500E-FG320(Spartan-3E fpga)92I/Oֹܽź12ֹܽš
ERROR:Pack:946 - The I/O component \has an illegal IOSTANDARD value.
Components of type DIFFMI do not support IOSTANDARD LVCMOS33. Please correct
the IOSTANDARD property value.
ΪֹܽõƽԣóLVCMOS33ӦΪоƬֵ֧LVDSƽ
οϣ
1LVDSFPGAĸͨѶӦоȺ http://www.eccn.com/xsj07/xsj080231.asp 2LVDSԭӦü
http://www.ent.eetchina.com/ART_8800472639_2700004_TA_5d4d019d.HTM
3) Ұ뵼ġLVDSûֲᡷ
http://www.ent.eetchina.com/ART_8800562170_2700004_TA_552cca6f.HTM
Xilinx FPGA ʹLVDS
http://www.61eda.com/Services/help/Xilinx/200803/1225.html
ʹHDL flowschematic flowֻҪIBUFDS,OBUFDS֮IJֻͿʹLVDSˡ
֮ҪλPinλãʹPACEIO
StandardѡLVDS33LVDS25ѡDCIİ汾˿ʱע⿴DatasheetPinַP/NPҲҪӦbufferеPNҲҪӦNעͬһbankֻһѹ
FPGA Editor۲첼ֲߺͻ֣ᷢFPGA
EditorûIBUFDSComponentBufferDzIOBģPinͼУԿһBufferIBUFDSá