Accelerated Graphics Port Interface Specification

AGP3.0 Interface Specification
Rev. 1.0
103
1010 Flush Similar to a Read. This request drives all low priority write
accesses ahead of it to the point that all the results are fully visible
to all other system agents, and then returns a single Quad-word of
random data as an indication of its completion. The address and
length fields are meaningless for this request.
1011 Reserved
1100 Fence (For both read and
writes)
All asynchronous writes prior to fence will become visible before
any asynchronous reads or writes completion following fence.
1101 Reserved (used for PCI
Frame based Dual
Address Cycle)
1110 ISOCH Align Returns the time offset from AGP3.0 isochronous period of core-
logic (or AGP3.0 bridge). The core-logic will treat this request as it
does a Read request and return a single aligned 32Byte value to
the Device. The length field for this transaction is 000. The core-
logic will return the data in the first word (4 bytes) in a common
clock cycle. The remaining 7 words in the common clock cycle will
have undefined data.
1111 Reserved