2–16

2.6.4

USBCTL: USB Control Register

Unlike the other registers, this register is cleared by the power-up-reset signal only. The USB reset cannot reset this

register (see the reset diagram in Figure 2–2).

7

6

5

4

3

210

CONT

U1/2

RWUP

FRSTE

RWE

B/S

SIR

DIR

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

BIT

NAME

RESET

FUNCTION

0

DIR

0

As a response to a setup packet, the MCU decodes the request and sets or clears this bit to reflect the data

transfer direction.

DIR = 0

USB data OUT transaction (from host to TUSB2136)

DIR = 1

USB data IN transaction (from TUSB2136 to host)

1

SIR

0

SETUP interrupt status bit. This bit is controlled by the MCU to indicate to the hardware when SETUP

interrupt is being served.

SIR = 0

SETUP interrupt is not served. The MCU clears this bit before exiting the SETUP interrupt

routine.

SIR = 1

SETUP interrupt is in progress. The MCU sets this bit when servicing the SETUP interrupt.

2

B/S

0

Bus/self power control bit

B/S = 0

The device is bus-powered.

B/S = 1

The device is self-powered.

3

RWE

0

Remote wake-up enable bit

RWE = 0

The MCU clears this bit when the host sends a command to clear the feature.

RWE = 1

The MCU writes 1 to this bit when the host sends set device feature command to enable the

remote wake-up feature.

4

FRSTE

1

Function reset connection bit. This bit connects/disconnects the USB function reset from the MCU reset.

FRSTE = 0

Function reset is not connected to MCU reset.

FRSTE = 1

Function reset is connected to MCU reset.

5

RWUP

0

Device remote wake-up request. This bit is set by the MCU and is cleared automatically.

RWUP = 0

Writing a 0 to this bit has no effect.

RWUP = 1

When the MCU writes a 1, a remote wake-up pulse is generated.

6

U1/2

0

USB hub version

U1/2 = 0

This is a USB1.x hub.

U1/2 = 1

This is a USB2.x hub.

7

CONT

0

Connect/disconnect bit

CONT = 0

Upstream port is disconnected. Pullup disabled

CONT = 1

Upstream port is connected. Pullup enabled