Dense Window Read Data Return Packet; Dense Window Read Data Return Packet Description - DEC AlphaServer 8200 Technical Manual

Figure 6-31

Dense Window Read Data Return Packet

UPD <31:0>
31 30 29 28 27 26 25
0 E VID
1*
2
3
4
5
6
7
8
9
* = clock cycle
Table 6-34 gives the description of the dense window read data return
packet.
Table 6-34 Dense Window Read Data Return Packet Description
Field Description
Is always zero.
Clock 1, <31>
Error. Set by the remote I/O bus adapter if any errors were detected on
Clock 1, <30>
the transfer.
Virtual ID of the TLSB commander node. This enables the I/O port to as-
Clock 1, <29:26>
sociate the packet with the originating commander node of the transac-
tion. This field is the same as the VID field in the Down Hose Dense Win-
dow Read Command packet being acknowledged.
Clock 1, <25:10> Are always zero.
Count field. Used by the I/O port to obtain the maximum number of win-
Clock 1, <9:6>
dow transactions the remote I/O bus adapter is capable of queueing. The
value in this field should always be the same for a specific remote bus I/O
adapter. The I/O port keeps track of the number of buffers that have been
filled.
NOTE: The I/O port sets the value of its remote adapter node buffer count
field to one at power-up or system initialization. The I/O port sets its re-
mote adapter node buffer count field to the value in this count field upon
receiving a Dense Window Read Data Return packet.
Clock 1, <5:0> Are always zero.
Bits <31:0> are return data longword 0 through 7, respectively, of the
Clocks 2 through
dense read.
9, <31:0>
10 9
Zero Count
Data Longword 0
Data Longword 1
Data Longword 2
Data Longword 3
Data Longword 4
Data Longword 5
Data Longword 6
Data Longword 7
UPCTL
6 5 0 3
1 1 0 1
Zero
x x x x
x x x x
x x x x
x x x x
x x x x
x x x x
x x x x
x x x x
BXB-0787-94
I/O Port 6-63
0