Microchip Technology EVB-USB7056, Руководство пользователя

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EVB-USB7056 Evaluation Board User’s Guide
DS50002887A-page 16  2019 Microchip Technology Inc.
3.1.1.2 EXTERNAL SPI FLASH
The EVB-USB7056 requires an external firmware image loaded to the on-board SPI
Flash. The external SPI Flash firmware is required to support USB PD functionality. The
EVB-USB7056 is shipped with a firmware image preloaded to the on-board memory.
The firmware revision can be quickly identified by enumerating the EVB-USB7056 to a
USB host PC and inspecting the USB Device ID (bcdDevice) of the USB2.0 or USB3.1
hub.
To properly boot from the SPI Flash, the following conditions must be met:
• Shunts are installed on J15 across pins 1-2 and 4-5.
• Any shunt installed on J12 is removed.
• A valid firmware image is loaded onto the SPI Flash device.
FIGURE 3-2: COMPONENTS CRITICAL FOR EXTERNAL SPI FLASH
FIRMWARE EXECUTION
The recommended sequence for reprogramming the SPI firmware is:
1. Install a shunt onto J12 to force booting from the internal ROM memory.
2. Reset the USB7056.
3. Connect the EVB-USB7056 to a USB host PC with a USB Type-A-to-Type-C
cable.
4. Boot the MPLAB Connect software and select the new firmware image.
5. Remove the shunt on J12.
6. Click the program button on MPLAB Connect.
3.1.1.3 INTERNAL ROM FIRMWARE
A basic hub firmware is included within the USB7056 internal ROM memory that may
be used as a boot-ROM for loading new firmware images into the external SPI Flash.
When the firmware is run from the internal ROM memory, the USB7056 basic hub fea -
tures will function, but the USB PD features will be non-functional. A USB
Type-A-to-Type-C adapter cable is recommended when running in this mode to ensure
that the attached host can reliably detect the USB hub and communicate with it.
SPI/Strap
Select (J15)
SPI Activity
LED (D12)