X01 Versions of the 2-Port USB5742 and 4-Port USB5744 SmartHub™ ICs
The USB5742 and the USB5744 are USB3.2 Gen 1 hubs offered by Microchip today. Both versions support an SKU called X01, which disables the usage of the internal USB device called the Hub Feature Controller (HFC). The HFC allows the USB host to access the internal MCU through USB commands. The internal MCU is the core technology that enables SmartHub™ ICs for Microchip’s USB product portfolio and is used for enabling additional features for the USB5742 and USB5744 (such as Input/Output bridging and FlexConnect), features that have no impact on the general usage of the USB3 hub.
The primary reason for disabling the HFC is so that it does not appear as part of the USB Tree. The output of the USB Tree can be seen by using an application such as USB View.
The USB device tree for both the standard and X01 versions are shown in the figure below. This view can be seen when plugging in an EVB-USB5744 into a USB3 port of a Windows® based Notebook. Note the X01 version has the Hub Feature Controller disabled.
To remove the HFC from the USB Tree, it must be disabled. The instructions are straightforward and can be implemented using the hub configuration tool, MPLAB® Connect Configurator, or by writing a series of configuration codes to the hub directly.
Configuration codes for the X01 SKUs are written to the hub during manufacturing, so the HFC is already permanently disabled.
The X01 version is a standard part with configuration codes added during the test. Customers can always use the standard version as an alternative solution if there are supply issues surrounding the X01.
Below is the list of X01 versions available from Microchip. There are silicon revisions on the X01 SKUs, so customers should migrate their existing A-step versions to B-step. All new designs should use the B revision silicon.
