82443GX Datasheet, PDF (108/128 Pages) Intel Corporation – Intel 440GX AGPset: 82443GX Host Bridge/Controller

Functional Description
Figure 4-5. External Glue Logic Drives CPU Clock Ratio Straps
HCLK
SUS_DIS strap
PCIRST#
PCLK
p_creset#
CRESET#
CPU straps
12
Suspend disable value latched when PCIRST# ↑
0 01 2
33,333
....
1 ms
CPU strap values from external Glue Logic
gx_time2.vsd
4.8.2.3
82443GX Straps
The 82443GX strapping options are latched in the rising edge of PCIRST#.
4.8.3 Suspend Resume
4.8.3.1 Suspend Resume protocols
The suspend resume sequences are indicated to the 82443GX by the PIIX4E, using SUS_STAT#,
and PCIRST#. In addition, the 82443GX contains NREF_EN and CRst_En configuration bits that
participate in the suspend resume sequences. As a result of suspend resume, the 82443GX
performs the following activities: Changing its refresh mode, performing internal and CPU reset
and Isolate or re-enable normal IO buffers.
Table 4-15. Suspend / Resume Events and Activities
State
SUSTAT# PCIRST# CrstEn
RESET
REFRESH
IO
BUFFERS
ON
assert inactive
POSCL/STR deassert active
POS
POSCCL
deassert inactive
deassert inactive
--
switch to suspend refresh isolate
-
reset exclude
resume/ref logic
suspend refresh
NREF_EN remains
inactive
enable
0 no resets
auto switch to normal ref
NREF_EN is set
enable
1
reset CPU only
auto switch to normal ref
NREF_EN is set
enable
4-28
82443GX Host Bridge Datasheet