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

Intel
®
Xeon™ Processor and Intel
®
E7500/E7501 Chipset Compatible Platform Design Guide 125
Intel
®
82870P2 (P64H2)
8.2.2.1 Manually-Operated Retention Latch Sensor
The HxSWITCH signal is monitored by the Hot-Plug controller to determine whether or not a slot
should be powered. The MRL sensor, or slot switch, should be connected to the HxSWITCH pin
such that it drives this pin low to indicate that the slot is closed and can be powered on. When the
signal is driven high, it indicates that the slot should immediately be powered off. The MRL Sensor
in represented schematically as a switch in Figure 8-12.
The Slot Present pins on each Hot-Plug slot are connected directly to the HxPRSNT2# and
HxPRSNT1# pins on the P64H2.
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
Ta b le 8 -19 for the corresponding P64H2 pin name.
Figure 8-12. Manually-Operated Retention Latch Sensor
Intel
®
P64H2
HxSWITCH
HxPRSNT1#
HxPRSNT2#
3.3 V
3.3V
Slot Present 1
Slot Present 2
Slot
MRL
Sensor
10 kΩ
330 Ω
5.6 kΩ
5.6 kΩ