TUSB2E221 datasheet(24/65 Pages) TI

24 / 65 page

8.4.4 Auto-Resume ECR

Optional host repeater auto-resume is supported by the TUSB2E221 in L1/L2 by driving Resume K at D+/D- until

SOResume is received from eDSPr. In addition, the TUSB2E221 eUSPh will hold Remote Wake line state until

SORresume is received from eDSPr.

This auto-resume feature provides the host controller extra time to exit low power state and issue SOResume

while the TUSB2E221 UDSP drives resume within 1ms (TURSM) hub resume timing requirement. To take

advantage of this low power feature, the host controller implements low power mechanism to detect wake on

eDSPr lines while host controller is in low power state.

This auto-resume feature is not required if host controller is capable of initiating SOResume within 1ms of

detecting Remote Wake on eDSPr.

This auto-resume ECR mode is disabled when L2 interrupt mode is enabled. When L2 interrupt mode is

enabled, resume K at D+/D- is still driven when Remote wake is detected on UDSP but eUSPh is held at SE0

instead of in Remote Wake state. See the L2 State Interrupt Modes section for more details.

Figure 8-1. Timing Diagram for Auto-Resume for HS/FS

8.4.5 L2 State Interrupt Modes

To prevent signaling on eUSB2 while the eDSP is powered off, enable both L2 remote wake interrupt and

disconnect event interrupt modes. The special remote wake sequence when L2 remote wake interrupt mode is

enabled.

• System enables interrupt USB_REMOTE_WAKE_Px.

• Repeater is in host mode and has received a CM.L2.

• Repeater detects wake on USB 2.0

• Repeater asserts interrupt.

• Repeater reflects resume on USB 2.0, but does not signal wake on eUSB2.

• Repeater waits for eDSPr to signal start of resume with no intervening configuration, connect, or reset

sequence.

• Repeater and eDSP follow normal eUSB2 protocol to signal resume starting and ending in L0.

Figure 8-2. Timing Diagram for Wake Interrupt for HS/FS

TUSB2E221

SNLS757B – JUNE 2024 – REVISED NOVEMBER 2024

www.ti.com

Submit Document Feedback

Product Folder Links: TUSB2E221

TUSB2E221 Datasheet(PDF) 24 Page - Texas Instruments