When feeding the descriptor information on the bypass input interface, the user
logic can request the QDMA Subsystem for PCIe to send a status
write back to the host when it is done fetching the data from the host. The user logic
can also request that a status be issued to it when the DMA is done. These behaviors can
be controlled using the sdi
and mrkr_req
inputs in the bypass input interface.
The H2C writeback status register is located after the last entry of the H2C descriptor list.
Note: The format of the H2C-ST status descriptor written to the descriptor ring
is different from that written into the interrupt coalesce entry.
Bit | Bit Width | Field Name | Description |
---|---|---|---|
[63:32] | 32 | reserved | Reserved |
[47:32] | 16 | pidx | Producer Index |
[31:16] | 16 | cidx | Consumer Index |
[15:2] | 14 | reserved | Reserved (Producer Index) |
[1:0] | 2 | error | Error 0x0 : No Error 0x1 : Descriptor or data error was encountered on this queue 0x2 and 0x3 : Reserved |