Intel 41210 manual Miscellaneous Signals, SMBus Interface Signals

Design Guide Checklist

Table 21. Miscellaneous Signals

	Signals	Recommendations		Reason/Impact
	RSTIN#	Used for debug purposes. Connect to VCC33 through
		an 8.2KΩ pullup resistor for normal operation.
	A_STRAP0,
	A_STRAP1,
	A_STRAP2,
	A_STRAP6,	These signals REQUIRE external pull-downs to GND
	B_STRAP0,
		on the board 8.2KΩ unless otherwise stated.
	B_STRAP1,
	B_STRAP2,
	B_STRAP6
	RESERVED [8:1]
		Input pin to configure 41210 to retry configuration
		accesses on it's PCI Express interface.
	CFGRETRY	• To retry configuration accesses to the 41210, pull high to
		3.3V through a 2K Ω resistor.
		• To allow configuration accesses to the 41210, ground this
		pin through a 2K Ω resistor.
	A_TEST1,
	A_TEST2,
	B_TEST1,
	B_TEST2
	A_PME#,	These signals REQUIRE an external pull-up, 8.2KΩ to
	B_PME#,	3.3V.
	A_STRAP[3],
	A_STRAP[4],
	A_STRAP[5],
	B_STRAP[3],
	B_STRAP[4],
	B_STRAP[5]
	NC17	This signal requires an external pull-up, 8.2KΩ to 3.3V.		In normal operating mode, this
				pin must be tied high.
Table 22. SMBus Interface Signals
	Signal	Recommendations		Reason/Impact
	SMBCLK	Connect to VCC33 through an 8.2KΩ	pullup resistor.
	SMBDAT	Connect to VCC33 through an 8.2KΩ	pullup resistor.
		SMBus addressing:
		Bit 7----------------’1’
		Bit 6----------------’1’
		Bit 5---------------SMBUS[5]
		Bit 4----------------’0’
	SMBUS[5],	Bit 3---------------SMBUS[3]		Sampled on the rising edge of
	SMBUS[3:1]	Bit 2---------------SMBUS[2]		PERST#.
		Bit 1---------------SMBUS[1]
		Use 8.2KΩ resistors as pullups to VCC33 for a ‘1’ and
		as pulldowns to ground for a ‘0’ to set the SMBus
		address.

62 Intel® 41210 Serial to Parallel PCI Bridge Design Guide