LSI LSI53C1030, Technical Manual

Page: 106 / 170

4-22 PCI Host Register Description
Version 2.1 Copyright © 2001, 2002, 2003 by LSI Logic Corporation. All rights reserved.
Register: 0xXX
Message Control
Read/Write
Reserved [15:8]
This field is reserved.
64-bit Address Capable 7
The PCI function sets this read only bit to indicate sup-
port of a 64-bit message address.
Multiple Message Enable [6:4]
These read/write bits indicate the number of messages
that the host allocates to the LSI53C1030. The host sys-
tem software allocates all or a subset of the requested
messages by writing to this field. The number of allocated
request messages must align to a power of two.
Table 4.3
provides the bit encoding of this field.
Multiple Message Capable [3:1]
These read only bits indicate the number of messages
that the LSI53C1030 requests from the host. The host
system software reads this field to determine the number
15 8 7 6 4 3 1 0
Message Control
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
Table 4.3 Multiple Message Enable Field Bit Encoding
Bits [6:4] Encoding Number of Allocated Messages
0b000 1
0b001 2
0b010 4
0b011 8
0b100 16
0b101 32
0b110 Reserved
0b111 Reserved