Ich4-M Checklist; Pci Interface And Interrupts - Intel 855GM Design Manual

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16.7.

ICH4-M Checklist

Note: All inputs to the ICH4-M must not be left floating. Many GPIO signals are fixed inputs that must be pulled up
to different sources.
16.7.1.

PCI Interface and Interrupts

Pin Name
PCI_DEVSEL#
PCI_FRAME#
PCI_GPIO0 / REQA#
PCI_GPIO1 / REQB_L/REQ5#
PCI_GPIO16 / GNTA#
PCI_IRDY#
PCI_LOCK#
PCI_PERR#
PCI_SERR#
PCI_STOP#
PCI_TRDY#
PCI_REQ[4:0]#
PCI_PME#
PCI_RST#, PAR, GNT[4:0]#,
GNTA#, GNTB#
APICCLK
APICD[1:0]
INT_IRQ[15:14]
INT_PIRQ#[A:D]
INT_PIRQE#/GPIO2
INT_PIRQF#/GPIO3
INT_PIRQG#/GPIO4
INT_PIRQH#/GPIO5
INT_SERIRQ
®
Intel 855GM/855GME Chipset Platform Design Guide
System Pull-up /Pull-down
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
None
0 Ω to gnd
10 k Ω pull-down to gnd
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
8.2 k Ω pull-up to Vcc3_3
Notes
Each signal requires a pull-up resistor.
GNTA is also used as a strap for "top block swap". It
is sampled on the rising edge of PWROK. By
default, this signal is HIGH (strap function
DISABLED). It can be enabled by a pull-down to gnd
through a 1-k Ω resistor.
Each signal requires a pull-up resistor.
ICH4-M has internal pull-up to VccSus3_3.
Can also be connected directly to ground.
If XOR chain testing is NOT used: Pull down the
signals through a shared 10 k Ω resistor. If XOR
chain testing is used: Each signal requires a
separate 10-k Ω pull-down resistor.
Each signal requires a pull-up resistor.
External pull up is required for INT_PIRQ#[A:D].
External pull up is required when muxed signal
(INT_PIRQ[E:H]#/ GPIO[2:5]) is implemented as
PIRQ.
Platform Design Checklist
301