USB7252SLASHKDX datasheet(33/65 Pages) MICROCHIP

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DS00002736D-page 33

USB7252

5.1.7

OTP CONFIGURATION STAGE (CFG_OTP)

Once the SOC has indicated that it is done with configuration, all configuration data is combined in this stage. The

default data, the SOC configuration data, and the OTP data are all combined in the firmware and the device is pro-

grammed.

5.1.8

HUB CONNECT STAGE (USB_ATTACH)

Once the hub registers are updated through default values, SMBus master, and OTP, the device firmware will enable

attaching the USB host by setting the USB_ATTACH bit in the HUB_CMD_STAT register (for USB 2.0) and the

USB3_HUB_ENABLE bit (for USB 3.2). The device will remain in the Hub Connect stage indefinitely.

5.1.9

NORMAL MODE (NORMAL_MODE)

Lastly, the hub enters Normal Mode of operation. In this stage full USB operation is supported under control of the USB

Host on the upstream port. The device will remain in the normal mode until the operating mode is changed by the sys-

tem.

RESET_N is asserted low, then Standby Mode is entered. The device may then be placed into any of the designated

hub stages. Asserting a soft disconnect on the upstream port will cause the hub to return to the Hub Connect stage until

the soft disconnect is negated.

Note:

If the same register is modified in both CFG_SMBUS and CFG_OTP stages, the value from CFG_OTP will

overwrite any value written during CFG_SMBUS.

USB7252/KDX 数据表(PDF) 33 Page - Microchip Technology