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why pcie_tx_st_ready keep low for almost 16384 pcie_clk

XG_Kang
Novice
223 Views

My FPGA design sends continueous MWr TLP packets  to CPU module on pcie gen2x4 link。The fpga design use Intel's  Arria10 PCIE HIP 。When sending contineous MWr TLP packets,the tx_st_ready signal of the PCIE HIP will be pulled down for almost 16384 pcie_coreclk cycles sometimes, and will be return to high for ready receiving TLP。Why the tx_st_ready signal be pulled down for so long cycles?how to shorten these low cycles?

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1 Solution
BoonT_Intel
Moderator
213 Views

Hello Sir,

Probably this is due to the receiver buffer at the host is out of credit limit. I believe the pull-down is expected if you send continuous back-to-back TLP packets.

Maybe you can find a way to increase the frequency of sending updateFC (credit update) packet from the receiver side. 


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2 Replies
BoonT_Intel
Moderator
214 Views

Hello Sir,

Probably this is due to the receiver buffer at the host is out of credit limit. I believe the pull-down is expected if you send continuous back-to-back TLP packets.

Maybe you can find a way to increase the frequency of sending updateFC (credit update) packet from the receiver side. 


BoonT_Intel
Moderator
202 Views

We do not receive any response from you to the previous question/reply/answer that I have provided. This thread will be transitioned to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.


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