Design Guide
105
Intel
®
82870P2 (P64H2)
8.2.5.6
Hot Plug Muxed Signals in Single Slot Parallel Mode
The Hot Plug signals that connect to the controller are as follows:
1. HPx_SLOT [N] are pull-ups/pull-downs. When in dual slot parallel mode, the external logic that decodes the
three-state value of PCIXCAP from the card must actively drive these signals to either logic 1 or logic 0 to
overcome the value of the pull-up/pull-down, and must be tri-stated during reset and while the card is not
connected to avoid damaging the slot count value.
2. The P64H2 must drive this signal to its corresponding state shown in
in case the system is set up
for single slot parallel mode so that LEDs are in the appropriate state (off), and the Q-switches remain
disconnected. Note that the placement of the signals should be such that the value driven by the P64H2 in
dual slot parallel mode is the same value it would have driven if in serial mode.
3. In parallel mode, the BUSEN# and CLKEN# signals become active low instead of active high as they are
during serial mode.
Figure 8-10. MUX Circuit Example
D
C
ENB
2:1 Multiplexer
VCC_3.3
PWROK
(PCIXCAP1 / PCIXCAP2) or HPxSLOT Strap
PCIXCAP1 / PCIXCAP2
1 k
Ω
Truth Table
C (PWROK)
D
HPxSLOT Strap
PCIXCAP1 / PCIXCAP2
0
1
S1
S2
This signal could be
pulled up to VCC_3.3
depending on the
strapping need.
8.2 k
Ω
Table 8-10. Single Slot Parallel Mode Hot Plug Signal Table
Signal
Type
Muxed With
Note
Bus A
Ball #
Bus B
Ball #
HxSWITCHA
I
PA_IRQ[15]
F4
PB_IRQ[15]
F1
HxFAULTA#
I
PA_IRQ[14]
E4
PB_IRQ[14]
E1
HxPRSNT2A#
I
PA_IRQ[13]
F5
PB_IRQ[13]
D1
HxPRSNT1A#
I
PA_IRQ[12]
E5
PB_IRQ[12]
C1
HxM66ENA
I/O
PA_IRQ[11]
D5
PB_IRQ[11]
B1
HxPCIXCAP1A
I
HPA_SLOT[2]
D20
HPB_SLOT[2]
D23 1
HxPCIXCAP2A
I
HPA_SLOT[1]
C20
HPB_SLOT[1]
C23 1
HxRESETA#
O
PA_GNT[5]
E22
PB_GNT[5]
G4 2
HxGNLEDA
O
HPA_SOC
A19
HPB_SOC
A24 2
HxAMLEDA
O
HPA_SOL
D19
HPB_SOL
C22 2
HxBUSENA#
O
HPA_SORR#
A18
HPB_SORR#
A22 2,
3
HxCLKENA#
O
HPA_SIL#
D24
HPB_SIL#
D24 2,
3
HxPWRENA
O
HPA_SOD
B19
HPB_SOD
C24
2
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 ...