USB84604 datasheet(27/61 Pages) MICROCHIP

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 2014-2016 Microchip Technology Inc.

DS60001295C-page 27

USB84604

6.0

DEVICE CONFIGURATION

The device supports a large number of features (some mutually exclusive), and must be configured in order to correctly

function when attached to a USB host controller. The hub can be configured either internally or externally depending on

the implemented interface.

Microchip provides a comprehensive software programming tool, Protouch, for configuring the USB84604 functions,

registers and OTP memory. All configuration is to be performed via the Protouch Programming Tool. For additional infor-

mation on the Protouch Programming Tool, contact your local Microchip sales representative.

6.1

Configuration Method Selection

The hub will interface to external memory depending on the configuration of the device pins associated with each inter-

face type. The device will first check whether an external SPI ROM is present. If present, the device will operate entirely

from the external ROM. When an external SPI ROM is not present, the device will check whether the SMBus is config-

ured. When the SMBus is enabled, it can be used to configure the internal device registers via the configuration registers

address space, or to program the internal OTP memory. If no external options are detected, the device will operate using

the internal default and configuration strap settings. The order in which device configuration is attempted is summarized

below:

SPI (Reading the configuration from an SPI ROM)

SMBus (either writing the configuration registers in the XDATA address space, or to OTP)

Internal default settings (with or without configuration strap over-rides)

6.2

Customer Accessible Functions

The following USB or SMBus accessible functions are available to the customer via the Microchip Protouch Program-

ming Tool.

6.2.1

USB ACCESSIBLE FUNCTIONS

6.2.1.1

I2C Master Access over USB

Access to I2C devices is performed as a pass-through operation from the USB Host. The device firmware has no knowl-

edge of the operation of the attached I2C device. The supported commands can be found on our web site at

www.microchip.com. Refer to the product page of the USB84604.

Note:

Refer to Chapter 7.0 Device Interfaces on page 31 for detailed information on each device configuration

interface.

Note:

For additional programming details, refer to the Microchip Protouch Programming Tool User Manual.

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