HC08KL8GRSSLASHD datasheet(87/256 Pages) NXP

87 / 256 page

System Integration Module (SIM)

SIM Counter

MC68HC08KL8 — Rev. 2.0

General Release Specification

System Integration Module (SIM)

8.4.2.5 Universal Serial Bus Reset

The USB module will detect a reset signaled on the bus by the presence

of an extended SE0 at the USB data pins of a device. The reset signaling

is specified to be present for a minimum of 10 ms. An active device

(powered and not in the suspend state) seeing a single-ended 0 on its

USB data inputs for more than 2.5

µs may treat that signal as a reset,

but must have interpreted the signaling as a reset within 5.5

µs. For a

low-speed device, an SE0 condition between 4 and 8 low-speed bit

times represents a valid USB reset. After the reset is removed, the

device will be in the attached, but not yet addressed or configured, state

(refer to Section 9.1 USB Devices of the

Universal Serial Bus

Specification Rev. 1.0). The device must be able to accept the device

address via a SET_ADDRESS command (refer to Section 9.4 of the

Universal Serial Bus Specification Rev. 1.0) no later than 10 ms after the

reset is removed.

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

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

8.5 SIM Counter

The SIM counter is used by the power-on reset module (POR) and in

stop mode recovery to allow the oscillator time to stabilize before

enabling the internal bus (IBUS) clocks. The SIM counter also serves as

a prescalar for the computer operating properly module (COP). The SIM

counter uses 12 stages for counting, followed by a 13th stage that

triggers a reset of SIM counters and supplies the clock for the COP

module. The SIM counter is clocked by the falling edge of CGMXCLK.

8.5.1 SIM Counter During Power-On Reset

The power-on reset module (POR) detects power applied to the MCU.

At power-on, the POR circuit asserts the signal PORRST. Once the SIM

is initialized, it enables the oscillator to drive the bus clock state machine.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

HC08KL8GRS/D Datasheet(PDF) 87 Page - NXP Semiconductors