Dense Window Read Command Packet; Sparse Window Write Command Packet Description - DEC AlphaServer 8200 Technical Manual

Table 6-20 Sparse Window Write 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 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.
Are always zero.
Clock 1, <25:15>
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.
Are always zero.
Clock 1, <11:4>
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:
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>
Clock 3 and 4 Data longword 0 and 1, respectively, to be written to the targeted remote
I/O bus.
<31:0>
Figure 6-20

Dense Window Read Command Packet

Clock cycle
31 30 29
0 0 VID
1
2
Table 6-21 gives the description of the Dense Window Read Command
packet.
6-48 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
11 Sparse configuration space
DND <31:0>
26 25
Zero
Byte Aligned Address <31:0>
15 14 13 12 11
0 1 1 Zero
0
2 1
SPC
BXB-0569-94