SMSC EVB-EMC1033 User Manual

EVB-EMC1002/EMC1033 User Manual

Revision 1.1 (12-14-06)

SMSC EMC1002/EMC1033

6

It is also possible to connect an external SMBus master to the EMC1002 EVB. A few modifications to
the circuit are required: 

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Cut 3 traces connecting JP4 pins 3-4, 5-6 and 7-8 on the bottom side of the PCB. This will 
disconnect the USB bridge from the SMBus. The pullup resistors for the SMBus SDA, SCL and 

Alert/Therm2

 signals are also disconnected so external pullups will need to be supplied by the 

SMBus Master.

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Install P1 or JP4 to provide an SMBus connector. See the Jumper Settings and Connection List 
for details. 

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Optionally remove zero ohm resistor R31. When removed, the USB to SMBus bridge will not supply 
+3.3V to the circuitry so power will need to be provided from an external source. If R31 is left 
installed, power will be supplied from the USB connector when connected to a computer or USB 
hub. 

Test points are provided for:

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Alert/Therm2

 output, EMC1002/1033 pin 6

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Addr

/

Therm

 output, EMC1002/1033 pin 4

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Ground

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+3.3V power

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+5V_USB power

LEDs indicate the status of the following signals:

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Alert/Therm2

, EMC1002/1033 pin 6

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Addr

/

Therm

, EMC1002/1033 pin 4

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+3.3V

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USB Activity - blinking indicates USB traffic

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Bridge Activity, when ON indicates the Bridge is functioning