Specifications

6-48 I/O Port
Table 6-20 Sparse Window Write Command Packet Description
Figure 6-20 Dense Window Read Command Packet
Table 6-21 gives the description of the Dense Window Read Command
packet.
Field Description
Clock 1, <31:30>
Are always zero.
Clock 1, <29:26>
Virtual ID of the TLSB commanding node. The VID indicates which CPU
is requesting the data. The VID indicates which CPU 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 com-
manding node with the data or status of the transaction.
Clock 1, <25:15>
Are always zero.
Clock 1, <14>
Indicates read/write: 0 is read, 1 is write. For this packet bit <14> is al-
ways one.
Clock 1, <13:12>
Command field. The field value is 11 for all window command packets.
Clock 1, <11:4>
Are always zero.
Clock 1, <3:2>
Byte length field, LEN<1:0>. The Length field decode is specific to the tar-
geted remote I/O adapter.
Clock 1, <1:0>
SPC<1:0> field. The space field indicates which PCI address space is in
use as follows:
SPC<1:0> PCI Address Space
00
01
10
11
Dense memory space (not used with this packet)
Sparse memory space
Sparse I/O space
Sparse configuration space
Clock 2, <31:27>
Byte-aligned address for the targeted remote I/O adapter. Bits <31:27>
are always zero.
Clock 2, <26:0>
Byte-aligned address <26:0> for the targeted remote I/O adapter.
Clock 3 and 4
<31:0>
Data longword 0 and 1, respectively, to be written to the targeted remote
I/O bus.
31 30 29 26 25 0
0 0 VID Zero Zero SPC
BXB-0569-94
1

2
Clock cycle
DND <31:0>
Byte Aligned Address <31:0>
15 14 13 12 11 12
110