Information

USBx_USBTRC0 field descriptions (continued)
Field Description
NOTE: It is always read as zero.
0 Normal USB module operation.
1 Returns the USB module to its reset state.
6
Reserved
This read-only field is reserved and always has the value zero.
5
USBRESMEN
Asynchronous Resume Interrupt Enable
This bit, when set, allows the USB module to send an asynchronous wakeup event to the MCU upon
detection of resume signaling on the USB bus. The MCU then re-enables clocks to the USB module. It is
used for low-power suspend mode when USB module clocks are stopped or the USB transceiver is in
Suspend mode. Async wakeup only works in device mode.
0 USB asynchronous wakeup from suspend mode disabled.
1 USB asynchronous wakeup from suspend mode enabled. The asynchronous resume interrupt differs
from the synchronous resume interrupt in that it asynchronously detects K-state using the unfiltered
state of the D+ and D- pins. This interupt should only be enabled when the Transceiver is suspended.
4–2
Reserved
This read-only field is reserved and always has the value zero.
1
SYNC_DET
Synchronous USB Interrupt Detect
0 Synchronous interrupt has not been detected.
1 Synchronous interrupt has been detected.
0
USB_RESUME_
INT
USB Asynchronous Interrupt
0 No interrupt was generated.
1 Interrupt was generated because of the USB asynchronous interrupt.
40.4.28 Frame Adjust Register (USBx_USBFRMADJUST)
Addresses: USB0_USBFRMADJUST is 4007_2000h base + 114h offset = 4007_2114h
Bit 7 6 5 4 3 2 1 0
Read
ADJ
Write
Reset
0 0 0 0 0 0 0 0
USBx_USBFRMADJUST field descriptions
Field Description
7–0
ADJ
Frame Adjustment
In Host mode, the frame adjustment is a twos complement number that adjusts the period of each USB
frame in 12-MHz clock periods. A SOF is normally generated every 12,000 12-MHz clock cycles. The
Frame Adjust Register can adjust this by -128 to +127 to compensate for inaccuracies in the USB 48-MHz
clock. Changes to the ADJ bit take effect at the next start of the next frame.
Memory map/Register definitions
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
916 Freescale Semiconductor, Inc.