3 Replies Latest reply on Sep 7, 2012 3:46 AM by rocky67

    Supported payload sizes

    mbouzaidi
      What payload sizes do your chipsets support?

      Dear AMD,

      According to the RS780 and RS690 ASIC Family Register Reference Guide, the only supported payload size for PCI express TLPs is 128 bytes. Is this the same for all current AMD northbridges? Or are there some that support different payload sizes?

      Thank you.

        • Supported payload sizes

          All of our chipsets behave the same way. 128B for DMA writes. 4K for DMA reads. 64B for DMA read completions. Host read/write requests are limited to 64B.

           

           

            • Re: Supported payload sizes
              doksam

              Hello,

              After three years, is this still true? All of AMD's chipsets including the new ones still behave the same way? 128B for DMA writes, 4KB for DMA reads, 64B for DMA read completions. Host read/write requests are limited to 64B.

               

              I am assuming this is your convention?

              DMA write - PCIe MWr from Device to Host

              DMA read - PCIe MRd from Device to Host

              DMA read completion - read completion from Host to Device

               

              Thanks.

              • Re: Supported payload sizes
                rocky67

                I find that all AMD chip sets work in the same manner. I understand that the payload size is not much but I need to know what supports different payload sizes