K66, Enet

[a8Chcx]

Hi,

I am using FRDM-K66, lwip raw API to do TCP connection. It works fine for normal operation.

When other device sends TCP every 100ms, TCP window size is changed to 0 after certain time. And it looks like K66 is not fast enough to procee TCP packets.

I am trying to speed up by using hardware checksum and DMA to do so and have the following problem:

1) When I enable "#define CHECKSUM_BY_HARDWARE" and didn't work. Can anyone help me on this?

2) Can anyone tell me how to use DMA?

Thanks,

Christie

[xiangjun_rong]

Hi,

I suppose that the ethernet module saves the packet into the buffer which is pointed by the pointer in receiver Buffer descriptor for receiver. For transmitter, the ethernet module transmits the packet saved in  the transmitter buffer which is pointed by the pointer in Transmitter Buffer descriptor.

So I think the DMA is not used.

Hope it can help you

BR

XiangJun Rong