
Chapter 4
Registers
179
24674
Rev. 3.00
April 2003
AMD-8111 HyperTransport I/O Hub Data Sheet
AMD Preliminary Information
HPE Timer 0 Con
fi
guration and Capabilities Register
HPET100
Default:
000F_DEFA_0000_0010h
Attribute:
See below.
Bits
63:32
T0_ROUTE_CAP.
These bits indicate to which interrupts in the IOAPIC this timer
’
s interrupt can be
routed. Each bit represents one interrupt. Bit63 represents interrupt 31, bit 32 interrupt0.
63:52: Read-only. Hardwired to 000000000000b IOAPIC does not support Interrupts 31 down to 20.
51:46: Read-writeOnce. These bits indicate if routing to INTIN19 down to INTIN14 of IOAPIC is
allowed.
45: Read-only. This bit is hardwired to 0b. Routing to INTIN13 of IOAPIC is not allowed.
44:41: Read-writeOnce. These bits indicate if routing to INTIN12 down to INTIN9 of IOAPIC is
allowed.
40: Read-only. This bit is hardwired to 0b. Routing to INTIN8 of IOAPIC is not allowed.
39:35: Read-writeOnce. These bits indicate if routing to INTIN7 down to INTIN3 of IOAPIC is allowed.
34: Read-only. This bit is hardwired to 0b. Routing to INTIN2 of IOAPIC is not allowed.
33: Read-writeOnce. This bit indicates if routing to INTIN1 of IOAPIC is allowed.
32: Read-only. This bit is hardwired to 0b. Routing to INTIN0 of IOAPIC is not allowed.
31:16 Reserved. Read-only. Hardwired to 0000h. Software should only write a 0000h to these bits.
15
T0_FSB_CAP.
Read-only. This bit is hardwired to 0 to
fl
ag that no FSB routing is possible.
14
T0_FSB_EN.
Read-only. This bit is hardwired to 0 to
fl
ag that no FSB routing is possible.
Description
13:9
T0_INT_ROUTE.
Read-write. This 5-bit
fi
eld de
fi
nes the routing to the IOAPIC. If the written value to
this register doesn
’
t match bits[63:32] of this register, then the most signi
fi
cant enabled interrupt is
written instead. If HPET10[LIEN] or bit14 of this register is set then these bits have no effect.
M32.
Read-only. This bit is hardwired to 0b, because the timer doesn
’
t support 64 bit mode and this bit
is not needed.
Reserved. Read-only. Hardwired to 0b. Software should only write a 0b to this bit.
SETVAL.
Read-write. Timer 0 Value Set. Software can set this bit to write the accumulator register of
periodic timer. Software should not set this bit, if this timer is not con
fi
gured as periodic timer. Software
has not clear this bit. It clears itself after writing HPET108.
SIZE.
Read-only. Hardwired to 0b to indicate that the timer is 32 bit only.
T0PCAP.
Read-only. Hardwired to 1b to
fl
ag, that this timer supports the periodic interrupt.
8
7
6
5
4