PCIE硬核作为endpoint时，如何主动发起通信？

[TWadu]

使用cyclone V芯片的pcie硬核，FPGA端作为EP，PC端作为RC。数据可以双向传输（通过DMA），但总是由RC发起的，即EP不能主动发起DMA传输，请问如果想EP主动发起传输，需要如何设置？或有哪些手册介绍？谢谢！

[SengKok_L_Intel]

This depends on how you control the Descriptor controller to initial DMA transfer. If this is your custom DMA descriptor controller, you probably can add some logic at the endpoint to control the DMA.

Regards -SK

[Shark121]

Hello, i face the same problem recently, and i'm new to this design. Could you explain what is the "Descriptor controller"? Is that in PCIe hard IP core?

[SengKok_L_Intel]

Hi,

The Descriptor controller is basically the brain of the whole DMA, and responsible to provide the descriptors to the movers to start the data transfer. This is not within the PCIe hard IP, you can use the descriptor controller that comes with the IP/reference design or you can build it on your own in order to have better control of it.

Regards -SK

[SengKok_L_Intel]

If further support is needed in this thread, please post a response within 15 days. After 15 days, this thread will be transitioned to community support. The community users will be able to help you with your follow-up questions.