Miscellaneous signals, Smbus interface signals – Intel 41210 User Manual

Page 62

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62

Intel® 41210 Serial to Parallel PCI Bridge Design Guide

Design Guide Checklist

Table 21. Miscellaneous Signals

Signals

Recommendations

Reason/Impact

RSTIN#

Used for debug purposes. Connect to VCC33 through
an 8.2K

Ω

pullup resistor for normal operation.

A_STRAP0,
A_STRAP1,
A_STRAP2,
A_STRAP6,

B_STRAP0,
B_STRAP1,
B_STRAP2,
B_STRAP6

RESERVED [8:1]

These signals REQUIRE external pull-downs to GND
on the board 8.2K

Ω

unless otherwise stated.

CFGRETRY

Input pin to configure 41210 to retry configuration
accesses on it's PCI Express interface.

•

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#,
B_PME#,
A_STRAP[3],
A_STRAP[4],
A_STRAP[5],
B_STRAP[3],
B_STRAP[4],
B_STRAP[5]

These signals REQUIRE an external pull-up, 8.2K

Ω

to

3.3V.

NC17

This signal requires an external pull-up, 8.2K

Ω

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 8.2K

Ω

pullup resistor.

SMBDAT

Connect to VCC33 through an 8.2K

Ω

pullup resistor.

SMBUS[5],
SMBUS[3:1]

SMBus addressing:

Bit 7----------------’1’

Bit 6----------------’1’

Bit 5---------------SMBUS[5]

Bit 4----------------’0’

Bit 3---------------SMBUS[3]

Bit 2---------------SMBUS[2]

Bit 1---------------SMBUS[1]

Use 8.2K

Ω

resistors as pullups to VCC33 for a ‘1’ and

as pulldowns to ground for a ‘0’ to set the SMBus
address.

Sampled on the rising edge of
PERST#.

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