Table of Contents
Advertisement
Table 6-19 Sparse Window Read Command Packet Description
Field
Description
Are always zero.
Clock 1, <31:30>
Virtual ID of the TLSB commanding node. The VID indicates which CPU
Clock 1, <29:26>
is requesting the data. The VID is returned on the Up Hose in all window
return data/status packets so that the I/O port can target the requesting
commanding node with the data or status of the transaction.
Are always zero.
Clock 1, <25:15>
Indicates read/write: 0 is read, 1 is write. For this packet bit <14> is al-
Clock 1, <14>
ways zero.
Command field. The field value is 11 for all window command packets.
Clock 1, <13:12>
Are always zero.
Clock 1, <11:4>
Byte length field, LEN<1:0>. The Length field decode is specific to the tar-
Clock 1, <3:2>
geted remote I/O adapter.
SPC<1:0> field. The space field indicates which PCI address space is in
Clock 1, <1:0>
use as follows:
Byte-aligned address for the targeted remote I/O adapter. Bits <31:27>
Clock 2, <31:27>
are always zero.
Byte-aligned address <26:0> for the targeted remote I/O adapter.
Clock 2, <26:0>
Sparse Window Write Command Packet
The Sparse Window Write command packet is used by processors to write
control and status registers in adapters on remote I/O buses that support
direct I/O window space.
A Sparse Window Write command packet must be acknowledged by a Win-
dow Write Status Return packet to the I/O port on the Up Hose. This
packet is supported by the I/O Window, Full, and Memory Channel vari-
ants of the hose protocol.
Figure 6-19 shows the Sparse Window Write Command packet.
6-46 I/O Port
SPC<1:0>
PCI Address Space
Dense memory space (not used with this packet)
00
Sparse memory space
01
Sparse I/O space
10
Sparse configuration space
11
Advertisement
Table of Contents
