mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 981

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

39.4.28 Frame Adjust Register (USBx_USBFRMADJUST)
Addresses: USB0_USBFRMADJUST is FFFF_9000h base + 114h offset = FFFF_9114h
Freescale Semiconductor, Inc.
USB_RESUME_
USBRESMEN
SYNC_DET
Reserved
Reserved
Field
Reset
Field
ADJ
4–2
INT
Read
7–0
Write
6
5
1
0
Bit
NOTE: It is always read as zero.
0
1
This read-only bit is reserved and always has the value zero.
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
1
This read-only bitfield is reserved and always has the value zero.
Synchronous USB Interrupt Detect
0
1
USB Asynchronous Interrupt
0
1
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.
7
0
Normal USB module operation.
Returns the USB module to its reset state.
USB asynchronous wakeup from suspend mode disabled.
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.
Synchronous interrupt has not been detected.
Synchronous interrupt has been detected.
No interrupt was generated.
Interrupt was generated because of the USB asynchronous interrupt.
USBx_USBTRC0 field descriptions (continued)
USBx_USBFRMADJUST field descriptions
0
6
MCF51JF128 Reference Manual, Rev. 2, 03/2011
0
5
Preliminary
0
4
Description
Description
ADJ
Chapter 39 Universal Serial Bus (USB) Controller
0
3
0
2
0
1
0
0
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