In the reference manual, it is said at chapter 18.104.22.168.1.2 : "Program your PCI Express system with a larger value of Max_Payload_Size without exceeding CX_MAX_MTU (128)."
I can't find any definition for CX_MAX_MTU but the number in parenthesis sugests that it's value is 128. Right ?
Does this means that the max payload size of PCIe packets is 128 bytes ? If true, this means that one can't trim the max payload size which min value is 128 bytes.