Byte Mask Field; Dense Window Write Command Packet Description - DEC AlphaServer 8200 Technical Manual

Table 6-22 Dense 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 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 one.
Command field. The field value is 11 for all window command packets.
Clock 1, <13:12>
Are always zero.
Clock 1, <11:2>
SPC<1:0> field. The space field indicates which PCI address space is in
Clock 1, <1:0>
use as follows:
SPC<1:0>
00
01
10
11
Byte aligned address for the targeted remote I/O adapter. Bits <31:27>
Clock 2, <31:0>
are always zero.
Data mask bits. The I/O port generates the byte mask bits from the valid
Clock 3, <31:0>
bits received on the second TLSB data cycle. The I/O port replicates each
longword valid bit it receives from the TLSB into 4-byte enables as shown
in Figure 6-22. All bytes of each valid longword will always be one.
Data longword 0 through 7, respectively, to be written to the targeted re-
Clock 4 through
mote I/O bus.
11, <31:0>
Figure 6-22

Byte Mask Field

Memory Chanel Write Packet
The Memory Channel Write packet is used by the I/O port to reflect a
TLSB memory space write to the remote I/O bus. When the hose is in nor-
mal mode, a Memory Channel Write packet must be acknowledged by a
Window Write Status Return packet (see Figure 6-22) to the I/O port on
the Up Hose. The Memory Channel Write packet is shown in Figure 6-23.
PCI Address Space
Dense memory space
Sparse memory space (not used with this packet)
Sparse I/O space (not used with this packet)
Sparse configuration space (not used with this packet)
LW7 LW6 LW5 LW4 LW3 LW2 LW1 LW0
1111 1111 1111 1111 1111 1111 1111 1111
BXB0801.AI
I/O Port 6-51