
158
Registers
Chapter 4
AMD-8111 HyperTransport I/O Hub Data Sheet
24674
Rev. 3.00
April 2003
AMD Preliminary Information
Miscellanous Register
DevB:0x4C
Default:
0000h.
Attribute:
Read-write.
Miscellanous Register
DevB:0x4E
Default:
C000h.
Attribute:
Read-write.
PCI Prefetching Control 0
DevB:0x50
Default:
0000 0000h.
Attribute:
see below.
1
0
Must be Low.
This bit is required to be Low at all times; if it is High then unde
fi
ned behavior results.
APICEN. IOAPIC enable.
0=Accesses to the IOAPIC memory mapped register space are ignored;
also, the dual 8259 PIC may generate interrupts through HyperTransport
messages. 1=The IOAPIC
is enabled; the PIC does not directly generate interrupt requests through HyperTransport messages
(although INTR goes through the IOAPIC redirection table, which may result in an interrupt request
HyperTransport message).
Bits
15:13 Reserved.
12
Must be Low.
This bit is required to be Low at all times; if it is High then unde
fi
ned behavior results.
11
Must be Low.
This bit is required to be Low at all times; if it is High then unde
fi
ned behavior results.
10
Must be Low.
This bit is required to be Low at all times; if it is High then unde
fi
ned behavior results.
9
Must be Low.
This bit is required to be Low at all times; if it is High then unde
fi
ned behavior results.
8
Must be Low.
This bit is required to be Low at all times; if it is High then unde
fi
ned behavior results.
7:0
Must be Low.
These bits are required to be Low at all times; if they are High then unde
fi
ned behavior
results.
Description
Bits
15:0
Description
Must be Low.
These bits are required to be set Low during initialization; if any bits are High then
unde
fi
ned behavior results.
Bits
31:24 Reserved.
23:21
[DPDM7, DPDH7, PFEN7_L]
. These bits apply to the PREQ_L/PGNT_L pair. See bits 2:0.
20:18
[DPDM6, DPDH6, PFEN6_L].
These bits apply to the REQ_L[6]/GNT_L[6] pair. See bits 2:0.
17:15
[DPDM5, DPDH5, PFEN5_L].
These bits apply to the REQ_L[5]/GNT_L[5] pair. See bits 2:0.
14:12
[DPDM4, DPDH4, PFEN4_L].
These bits apply to the REQ_L[4]/GNT_L[4] pair. See bits 2:0.
11:9
[DPDM3, DPDH3, PFEN3_L].
These bits apply to the REQ_L[3]/GNT_L[3] pair. See bits 2:0.
8:6
[DPDM2, DPDH2, PFEN2_L].
These bits apply to the REQ_L[2]/GNT_L[2] pair. See bits 2:0.
Description
Bits
Description (Continued)