Intel Xeon Processor and Intel E7500/E7501Chipset Compatible Platform Design Guide

Intel
®
82870P2 (P64H2)
126 Intel
®
Xeon™ Processor and Intel
®
E7500/E7501 Chipset Compatible Platform Design Guide
8.2.2.2 Optional Attention Button
The Attention Button state is observed on the slot-specific HxPRSNT1# pin. An exclusive-OR
(XOR) gate is inserted between the Slot Present signal and the Hot-Plug controller as shown in
Figure 8-13. A momentary contact button is connected to the other input of the XOR gate. When
the button is in the released state, the Slot Present signal is unaffected. When the button is actively
being pressed/asserted, the Slot Present signal is inverted, signaling the Hot-Plug controller to
commence slot power up/down sequence.
NOTE: The pin names shown in the Intel P64H2 block are hot-plug slot signal names. For single-slot parallel
mode, refer to Table 8-17 for the corresponding P64H2 pin name. For dual-slot parallel mode, refer to
Table 8-19 for the corresponding P64H2 pin name.
8.2.3 LED Indicator Outputs
The PCI Hot-Plug Standard Usage Model assumes that the platform provides two indicators per
slot. Indicators must be placed in close proximity to their associated slot so that the association
between the indicators and the Hot-Plug slot is clear.
The LED output signals for all modes of P64H2 Hot-Plug controller operation are active high. In
all cases, the green LED is the power indicator, and the amber LED is the attention indicator.
8.2.4 Hot Plug Interrupt Routing Requirements
The recommended method to support hot plug is to route the SCI interrupt output signal on the
P64H2 (pin PAIRQ7) to an available GPIO pin on the ICH3. A System Controlled Interrupt (SCI)
is a system interrupt used by hardware to notify the operating system of ACPI events. SCI is an
active-low, shareable, level-triggered interrupt.
Figure 8-13. Attention Button Implementation
Intel
®
P64H2
HxSWITCH
HxPRSNT1#
HxPRSNT2#
3.3 V
3.3V
Slot Present 1
Slot Present 2
MRL Sensor
Attention
Button
XOR
Slot
330 Ω
1 kΩ
3.3V
10 kΩ
5.6 kΩ
5.6 kΩ