Intel
®
82870P2 (P64H2)
106
Design Guide
8.2.5.7
SMBus Address Considerations
In Single Slot Parallel mode, the SMBus address strap pins listed in
are muxed with Hot
Plug control signal HxRESETA#. Therefore, it is recommended that the following technique be
used for determining an SMBus address. Pull the PA_GNT5 (RESETA#) signal to ground through
a 100
k
Ω
± 5% resistor. This will keep the reset signal active until the P64H2 is ready for it to
become deasserted. Pull the PA_GNT4 (Hx_BUSENB#) signal to 3.3 V through a 10
k
Ω
± 5%
resistor. The P64H2 will be able to drive this signal to ground when the signal must be asserted.
8.2.5.8
Pull-Ups/Pull-Downs in Single Slot Parallel Mode
All PCI signals should follow the
PCI Local Bus Specification, Revision 2.2
pull-up requirements
whether they are muxed or not. All unused input signals should be pulled to 3.3 V through an
8.2
k
Ω
± 5% resistor to keep them from floating.
defines which muxed signals are to be used with single slot mode. Note that whether in
single or dual slot mode, all signals from
are actually muxed even though only the
signals listed in
are used. As a result, all unused input signals listed in
must
be pulled to 3.3 V through an 8.2
k
Ω
± 5% resistor to keep them from toggling.
Table 8-11. Hot Plug Controller Output Signal Reset Values
Signals
Reset Value
Px_GNT[5:3]
011
HPx_SOC
0
HPx_SIC
0
HPx_SOL
0
HPx_SOLR
0
HPx_SOD
0
HPx_SORR#
1
HPx_SOR#
0
HPx_SIL#
1
Figure 8-11. Single Slot Parallel SMBus Circuit
HX_BUSENB#
HX_RESETA#
Slot 1
100 k
Ω
3.3V
Intel
®
P64H2
10 k
Ω
Summary of Contents for Xeon
Page 24: ...Introduction 24 Design Guide This page is intentionally left blank ...
Page 30: ...Component Quadrant Layout 30 Design Guide This page is intentionally left blank ...
Page 52: ...Platform Clock Routing Guidelines 52 Design Guide This page is intentionally left blank ...
Page 66: ...System Bus Routing Guidelines 66 Design Guide This page is intentionally left blank ...
Page 118: ...Intel 82870P2 P64H2 118 Design Guide This page is intentionally left blank ...
Page 146: ...I O Controller Hub 146 Design Guide This page is intentionally left blank ...
Page 148: ...Debug Port 148 Design Guide This page is intentionally left blank ...
Page 210: ...Schematic Checklist 210 Design Guide This page is intentionally left blank ...
Page 220: ...Layout Checklist 220 Design Guide This page is intentionally left blank ...
Page 222: ...Schematics 222 Design Guide This page is intentionally left blank ...