TUSB322I

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SLLSEO5 – OCTOBER 2015

Feature Description (continued)

Table 3. Supported Features for the TUSB322I Device by Mode

SUPPORTED

DFP-Only

UFP-Only

DFP

FEATURES

Port attach and

Yes

Yes

Yes

detach

Cable orientation

Yes

Yes

Yes

Cable orientation

Yes

Yes

Yes

through DIR pin

Current advertisement

Yes

—

Yes (DFP)

Current detection

—

Yes

Yes (UFP)

Accessory modes

Yes

Yes

Yes

(audio and debug)

Active cable detection

Yes

—

Yes (DFP)

Try.SRC

—

—

Yes (DFP)

Try.SNK

—

—

Yes (UFP)

VCONN

Yes

—

Yes (DFP)

Yes

Yes

Yes

Legacy cables

Yes

Yes

Yes

—

Yes

Yes (UFP)

7.3.2.1 Downstream Facing Port (DFP) - Source

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

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. This limitation is a

result of a backwards compatibility problem between USB Type-C 1.1 DFP and a USB Type-C 1.0 DRP.

7.3.2.2 Upstream Facing Port (UFP) - Sink

The TUSB322I device can be configured as a UFP-only by changing the MODE_SELECT register default

setting. In UFP mode, the TUSB322I device constantly presents pulldown resistors (Rd) on both CC pins. The

TUSB322I device monitors the CC pins for the voltage level corresponding to the Type-C mode current

before successfully attaching. As a UFP, the TUSB322I device detects and communicates the advertised current

state.

Steps for enabling UFP-only:

1. Write a 1'b1 to DISABLE_TERM register (address 0x0A bit 0).

2. Write a 2'b01 to MODE_SELECT register (address 0x0A bits 5:4)

3. Write a 1'b0 to DISABLE_TERM register (address 0x0A bit 0).

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