mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 1015

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Chapter 40 USB Device Charger Detection Module (USBDCD)
The USBDCD module is compatible with systems that do not check the strength of the
battery. Therefore, this module assumes that the battery is good, so the USB device must
immediately connect to the USB bus by pulling the D+ line high after the USBDCD
module has determined that the device is attached to a charging port. The module is also
compatible with systems that do check the strength of the battery. In these systems, if it is
known that the battery is weak or dead, software can delay connecting to the USB while
charging at 1.5A. Once the battery is charged to the good battery threshold, software can
then connect to the USB host by pulling the D+ line high.
40.7.3 Handling Unplug Events
If the device is unplugged from the USB bus during the charger detection sequence, the
contents of the STATUS register should be ignored and the USBDCD module should get
a Sotware Reset, as described in
Software
Reset.
MCF51JF128 Reference Manual, Rev. 2, 03/2011
Preliminary
Freescale Semiconductor, Inc.
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