Functional Description
4.8.2
82443BX Reset
The 82443BX reset function is an integral part of the suspend resume functions. The 82443BX
supports the normal reset function in a desktop platform, as well as the various power-up reset and
resume reset functions in the mobile platform. In this section, the power-up reset is described. The
resume from suspend sequences are described in the following section.
Table 4-15. AGPset Reset
CPURST#
CRESET#
NBX#
Pentium® Pro
Processor
A20M#, IGNNE#,
INTR, NMI
INIT#
SUB_STAT1#
4x
2to1 Mux
PCIRST#
PIIX4E#
External CPU
Clock Ratio
Straps
RSTDRV
PWROK
External CPU Strap Glue
:
Table 4-16. Reset Signals
Asserted
with PCIRST#
System Devices or
Buses Affected
Signal
Source
Signal
Description
PCI bus, 82443BX
NB, PIIX4E
PCIRST# is used in power -up sequence
as well as resume from STR or STD.
PCIRST#
-
PIIX4E
CPU reset signal. CPURST# pin resides
in 82443BX.
CPURST#
Always
CPU
82443BX
PIIX4E
ISA bus reset. Directly derived from
PCIRST#. Resides in PIIX4E main
voltage well.
ISA bus / X-Bus
devices
RSTDRV
Always
SUS_STAT# signals a suspend mode
entry and exit. Both signals originate
from PIIX4E in its suspend voltage well.
PIIX4E
only
SUS_STAT#
INIT#
N/A
No
CPU
PIIX4E
CPU Soft Reset generated by PIIX4E.
4-32
82443BX Host Bridge Datasheet
ETC [ ETC ]
