FPGA+外部PHY+SFP光口问题

a294558772

检查，接口信号线上下拉电阻

saigu

回复 31# a294558772


   跟手册电路一致。   而且我SFP电口可以，从电路上说，电口SFP和光口SFP是一样的，只是SFP模块内部的区别，所以不知道为什么光口就不行了。

右手边

回复 32# saigu
spf你按照我发的那个图添加上拉电阻试试

saigu

回复 33# 右手边


   哪里的上拉电阻？我尝试了去掉C113，然后在接收信号的差分信号上加了电阻，然后也没有用。

anovickis

the LOS is just optical power indication it is not specific to to any signaling rate -
As long as TXDISABLE on is LOW on both ends should have LOS low

Perhaps check independantly that laser is on (You can usually use cheap CCD camera like cell phone or whatever method to check)

Is TX fiber connected to RX fiber input  ?

右手边

在SGMII接口处按这种电路连接，应该可以解决吧

saigu

回复 35# anovickis


   Thanks a lot.
   I tried to configure the Tx_disable pin at low conditon with FPGA, but it didn't work. Today I suddenly think about that why not try to configure the Tx_diable pin at low condition with AGND net, and it finally come to a good result.
   It seems that the FPGA can not configure the pin right, and it is not reasonable. Although I do not know why the FPGA control can not work, it doesn't matter.

   It was your advice that as long as TXDISABLE on is LOW on both ends should have LOS low which gave me a sudden inspiration.
    Thanks a lot again.

saigu

回复 36# 右手边


   问题已解决，万分感谢一直以来的帮助！   我会在首楼贴出原因。

右手边

回复 38# saigu


   恭喜，谢谢分享。

livelei

congratulations