3.8

Accessory mode detection

The STUSB1602 supports the detection of audio accessory mode and debug accessory mode as defined

in the USB Type-C standard specification with the following Type-C power modes (see Section 6 Start-up

configuration):

•

Source power role with accessory support

•

Sink power role with accessory support

•

Sink power role without accessory support

•

Dual power role with accessory support

3.8.1

Audio accessory mode detection

The STUSB1602 detects an audio accessory device when both CC1 and CC2 pins are pulled down to

CC_ATTACHED_MODE bits of the I²C register CC_CONNECTION_STATUS.

3.8.2

Debug accessory mode detection

The STUSB1602 detects a connection to a debug and test system (DTS) when it operates either in sink power

role or in source power role. The debug accessory detection is advertised by the DEBUG1 and DEBUG2 pins as

well as through the CC_ATTACHED_MODE bits of the I²C register CC_CONNECTION_STATUS.

•

In sink power role, a debug accessory device is detected when both the CC1 and CC2 pins are pulled up by

an Rp resistor from the connected device. The voltage levels on the CC1 and CC2 pins give the orientation

and current capability as described in the table below. The DEBUG1 pin is asserted to advertise the DTS

detection and the A_B_SIDE pin indicates the orientation of the connection. The current capability of the

DTS is given through the SINK_POWER_STATE bits of the I²C register CC_OPERATION_STATUS.

#

CC1 pin

(CC2 pin)

CC2 pin (CC1 pin)

Charging

current

configuration

A_B_SIDE pin

CC1/CC2

(CC2/CC1)

Current capability state

SINK_POWER_STATE

bit values

1

Default

HiZ (0)

PowerDefault.SNK (source

supplies default USB

current)

2

1.5 A

HiZ (0)

Power1.5.SNK (source supplies 1.5 A USB Type-C current)

3

3.0 A

HiZ (0)

Power3.0.SNK (source

supplies 3.0 A USB Type-C

current)

Default

HiZ (HiZ)

PowerDefault.SNK (source

supplies default USB

current)

•

In source power role, a debug accessory device is detected when both the CC1 and

CC2 pins are pulled down to ground by an Rd resistor from the connected device. The orientation detection

is performed in two steps as described in the table below. The DEBUG2 pin is asserted to advertise the

DTS detection and the A_B_SIDE pin indicates the orientation of the connection. The orientation detection is

advertised through the TYPEC_FSM_STATE bits of the I²C register CC_OPERATION_STATUS.

STUSB1602

Accessory mode detection

DS11254 - Rev 5

page 15/39