
Chapter 4
Registers
175
24674
Rev. 3.00
April 2003
AMD-8111 HyperTransport I/O Hub Data Sheet
AMD Preliminary Information
The interrupt definition registers are defined as follows:
4.4.6
Watchdog Timer Registers
The Watchdog Timer Registers are non-enumerable memory mapped I/O registers. The base address
is controlled by DevB:0xA8. All register can be accessed by 32-bit memory accesses.
Table 55.
Watchdog Timer Registers
Bits
63
Description
Wait for EOI.
Read-write. This bit is set by hardware when an interrupt request is sent and cleared by
hardware when the EOI is returned. Software may write a 1 to clear this register without an EOI so
that the device can send another interrupt. Writing 0 has no effect. This bit is not de
fi
ned if RQEOI is
clear.
PassPW.
Read-write. 1= the HyperTransport
interrupt message will have the pass PW bit set and is
allowed to pass other posted requests. 0= the pass PW bit in the interrupt message will be clear.
61:56 Reserved.
55:32
IntrInfo[55:32].
Read-write. These bits contain the interrupt information bits 55:32 which are send in
the interrupt message.
31:24
IntrInfo[31:24].
Read-write. These bits contain the interrupt information bits 31:24 which are send in
the interrupt message. Should be programmed to F8h for compliance with earlier HyperTransport
technology implementations.
23:6
IntrInfo[23:6].
Read-write. These bits contain the interrupt information bits 23:6 which are send in the
interrupt message.
5
RQEOI. Request EOI.
Read-write. When set, after each interrupt request is sent the device waits for
an EOI (or software clears the wait for EOI bit) before sending another interrupt.
4:2
Message Type.
Read-write. Speci
fi
es the type of interrupt. See HyperTransport technology
speci
fi
cation 1.02 for valid settings.
1
Polarity.
Read-write. This bit is only valid for external interrupt sources (e.g., pins). 1= The interrupt
signal is active-Low. 0= The interrupt signal is active-High.
0
Mask.
Read-write. 1= Interrupt masked, no interrupt is sent from this source (default). 0= Interrupt
can be sent.
62
Address
00h
08h
Mnemonic
WDT00
WDT08
Name
Default
0000_0008h
0000_0000h
Watchdog Timer Control/Status Register
Watchdog Timer Count Register