pcie处理层协议中文详解(12)

所有的Message包都用Msg编码，即不包括数据负荷的Message包，除了Vendor_Defined Messages和

Set_Slot_Power_Limit Message包，Message包有以下限制：

□ The Message Code field must be fully

decoded (Message aliasing is not permitted).

□ Except as noted, the Attr[1:0] field is reserved.

保留Attr域。

□ AT[1:0] must be 00b.

□ Except as noted, bytes 8 through 15 are

reserved.保留包头部分的bytes8到byte15.

□ Message Requests are posted and do not

require Completion.Message包不需要返回响应包。

□ Message Requests follow the same ordering

rules as Memory Write Requests.

寻址方式：隐含寻址，由Type域中的r[2:0]决定，即Type域的最后三位。具体寻址映射如下：