喜
我有一个设计,我连接了2个
FPGA- 一个vlx75T(发送125MHz clk和txdata)到vlx760 FPGA。
并且vlx760 FPGA在由vlx75生成的相同clk处将数据(rxdata)发送回vlx75T。
有连接器
在FPGA之间连接它们。
我想知道 -
1)为进入vlx760t FPGA的txdata和clk线的约束添加偏移是“强制性的”吗?
甚至没有约束的偏移,设计仍然可以工作?
2)我的想法是,由于clk和txdata来自相同的源并具有相同的路径/互连延迟,因此在这种情况下进入vlx760 FPGA的clk和txdata不需要在约束中作为两条线路上的延迟进行偏移
会是一样的。
我的理解是正确的吗?
如果我的理解不正确,那么在什么情况下我需要使用偏移输入/输出约束?
3)我需要从vlx760到vlx75 fpga的rxdata的偏移约束吗?
4)由于clk为125MHz,因此设计无法满足vlx760 fpga的时序要求。
将偏移输入/输出约束添加到vlx760 fpga - IN ANY WAY - 帮助满足125MHz周期约束?
帮帮我 !!!
:)
ž。
以上来自于谷歌翻译
以下为原文
hi,
i have a design where i have connected 2 FPGAs - a vlx75T (which sends a 125MHz clk and txdata) to a vlx760 FPGA. and the vlx760 FPGA sends back data (rxdata) to vlx75T at the same clk generated by vlx75. there is connector in
between the FPGAs to connect them. I wanted to know -
1) is it "compulsary" to add offset in constraints for the txdata and clk lines going into the vlx760t FPGA? or even without the offset in constraint, the design can s
till work?
2)My thinking is that since the clk and txdata are coming from the same source and have the same path/interconnect delay so in that case the clk and txdata going into the vlx760 FPGA donot need offset in constraint as the delay on both the lines will be the same. is my understanding correct?
If my understanding is not correct, then in what case will i need to use the offset in/out constraints?
3) do i need offset out constraint for the rxdata going from vlx760 to vlx75 fpga?
4) since the clk is 125MHz, the design is failing to meet timing on the vlx760 fpga. will adding the offset in/out constraints to vlx760 fpga - IN ANY WAY - help meet the 125MHz period constraint ?
help !!! :)
z.
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