Intel 41210 manual AM66EN, BM66EN PERST#, Apcixcap, Bpcixcap, Idsel

			Design Guide Checklist
Table 20. PCI/PCI-X Interface Signals
	Signals	Recommendations	Reason/Impact
		Controls frequency of the PCI segment when running
		in conventional PCI mode (33 MHz or 66 MHz):
		0 = 33 MHz PCI
		1 = 66 MHz PCI
	A_M66EN	• Pull-up using a 8.2KΩ resistor when the PCI bus is	Sampled on the rising edge of
		to operate at 66 MHz and not already pulled up by
	B_M66EN		PERST#.
		system board. This signal is grounded for 33 MHz
		operation.
		• Connect M66EN to a 0.01 µF capacitor located
		with-in 0.25 inches of the M66EN pin on the PCI
		connector (for designs with secondary PCIX bus
		slots only).
			• Design without secondary PCI/PCI-
			X Slot
			— If there is at least one legacy
			PCI device on the PCI/PCI-X
			bus, tie this pin directly to
			GND.
			— If all devices are PCI-X
			capable and there is at least
			one PCI-X device that only
			supports maximum PCI-X
			66MHz on the secondary PCI
			bus, pull down to GND
			through 10KΩ series resistor
			parallel with a 0.01uF
			capacitor.
			— If all secondary PCI-X
			devices (and the bus loading)
			support PCI-X 133MHz,
	A_PCIXCAP	Connects directly to the PCIXCAP pin on the PCI slot.	connect PCIXCAP to 3.3V
	B_PCIXCAP	Connect to VCC33 through an 8.2KΩ pullup resistor.	through an 8.2K Ω resistor
			• Design with secondary PCI/PCI-X
			Slot
			— If there is at least one on
			board legacy PCI device on
			the secondary PCI bus, tie
			this pin directly to GND.
			— Else
			•Pull up to 3.3V through a
			8.2KΩ resistor
			•Connect this pin to
			PCIXCAP (Pin B38) of the
			PCI connector. (Assuming
			bus loading supports up to
			PCI-X 133MHz)
	IDSEL	The series resistor on IDSEL should be 200Ω ±5%.

Intel® 41210 Serial to Parallel PCI Bridge Design Guide 61