2 i2c bus power domains, 3 i2c pm bus i/o expanders, I2c bus power domains – Kontron SMARC Evaluation Carrier User Manual

Page 59: I2c pm bus i/o expanders

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User’s Guide

59

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miscellaneous control

5

TI TCA9554

IO Expander

U33

0x24

0x48 / 0x49

Miscellaneous control

6

Wolfson

WM8903

Audio Codec

U54

0x1B

0x36 / 0x37

7

NS LP8545

Backlight

LED Supply

U16

0x54

May not be visible – this

device has PWM and I2C

modes – initial builds are

with PWM modes.

I2C_CAM Bus

1

Atmel AT24HC02 EEPROM

U31

0x54

0xA8 / 0xA9

HDMI I2C Bus

1

No HDMI I2C devices on

the Eval Carrier. I2C

device(s) should be visible

if an HDMI display is

connected.

15.2 I2C Bus Power Domains

The Evaluation Carrier I2C_PM bus devices are in the Module Power Domain, and not in the Carrier Power Domain. This

allows the Module to use the I2C_PM bus for monitoring and controlling power on the Evaluation Carrier. The other I2C

buses (I2C_LCD, I2C_GP, I2C_CAM, and HDMI) are in the Carrier Power Domain.

15.3 I2C PM Bus I/O Expanders

There are two I/O expanders on the I2C_PM bus. One is used to enable / disable various power rails on the Evaluation

Carrier, and the other to monitor the Power Good status of most these rails.

The use of these I/O expanders is optional, and the Evaluation Carrier can function without any manipulation of these

devices. The devices power up such that all of their I/O pins are inputs, and pull-up or pull-down resistors ensure that

the default function is in the ‘Enabled’ state.

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