SLLSEO5D October 2015 – March 2021 TUSB322I
PRODUCTION DATA
The TUSB322I device can be configured as a DFP-only device by changing the MODE_SELECT register default setting. In DFP mode, the TUSB322I device constantly presents Rps on both CC. In DFP mode, the TUSB322I device initially advertises default USB Type-C current. The Type-C current can be adjusted through I2C if the system is required to increase the amount advertised. The TUSB322I device adjusts the Rps to match the desired Type-C current advertisement. As a DFP, the TUSB322I monitors the voltage level on CC pins looking for the Rd termination of a UFP. When a UFP is detected and TUSB322I is in the Attached.SRC state, the TUSB322I will supply VCONN on the CC pin that has Ra.
The following list describes the steps for enabling DFP-only.
1. Write a 1'b1 to DISABLE_TERM register (address 0x0A bit 0)
2. Write a 2'b10 to MODE_SELECT register (address 0x0A bits 5:4)
3. Write a 1'b0 to DISABLE_TERM register (address 0x0A bit 0)
When configured as a DFP, the TUSB322I can operate with older USB Type-C 1.0 devices except for a USB Type-C 1.0 DRP device. The TUSB322I cannot operate with a USB Type-C 1.0 DRP device. The limitation is a result of a backwards compatibility problem between USB Type-C 1.1 DFP and a USB Type-C 1.0 DRP.