Example 3: Posted Byte Write Request

The Host Bridge in Figure 7-5 on page 157 is targeting I/O address space in Device 2 (UnitID2) with a posted, sized (byte) write of three bytes.

Figure 7-5. Posted WrSized (Byte) Write Targeting A Downstream Device

Example 3: WrSized (Byte) Request Packet Setup

(Refer to [1] in Figure 7-5 on page 157)

Command[5:0] Field (Byte 0, Bit 5:0)

This is the sized write (WrSized) control packet command code. The option bits within this field: the posted (bit 5), dword (bit 2), Isoc (Bit 1), and coherency (bit 0) are all (cleared = 0), meaning the request is non-posted, uses byte data size, travels in the standard virtual ...

Get HyperTransport™ System Architecture now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.