HC08KL8GRSSLASHD datasheet(116/256 Pages) NXP

116 / 256 page

Universal Serial Bus Module (USB)

General Release Specification

MC68HC08KL8 — Rev. 2.0

Universal Serial Bus Module (USB)

9.3.4.2 USB Reset Signalling

Reset can wake a device from the suspended mode. A device may take

up to 10 ms to wake up from the suspended state.

9.3.4.3 Remote Wakeup

The MC68HC08KL8 also supports the remote wakeup feature. The

firmware has the ability to exit suspend mode by signaling a resume

state to the upstream host or hub. A non-idle state (K state) on the USB

data lines is accomplished by asserting the FRESUM bit in the UCR1

When using the remote wakeup capability, the firmware must wait for at

least 5 ms after the bus is in the idle state before sending the remote

wakeup resume signaling. This allows the upstream devices to get into

their suspend state and prepare for propagating resume signaling. The

FRESUM bit should be asserted to cause the resume state on the USB

data lines for at least 10 ms, but not more than 15 ms. Note that the

resume signalling is controlled by the FRESUM bit and meeting the

timing specifications is dependent on the firmware. When FRESUM is

cleared by firmware, the data lines will return to their high-impedance

state. Refer to the register definitions (see 9.6.5 USB Control Register

1) for more information about how the force resume (FRESUM) bit can

be used to initiate the remote wakeup feature.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

HC08KL8GRS/D Datasheet(PDF) 116 Page - NXP Semiconductors