mcf5274l Freescale Semiconductor, Inc, mcf5274l Datasheet - Page 28

• Manufacturer Part Number: mcf5274l
• Description: Mcf5275 Integrated Microprocessor Family Hardware
• Manufacturer: Freescale Semiconductor, Inc

Signal Descriptions
4.11 USB Signals
Table 13
28
Clear-to-Send
Request-to-Send
USB Clock
USB Speed
USB Received D-
USB Received D+
USB Receive Data
USB Suspended
USB Transmitted D-
Signal Name
Signal Name
describes the USB serial interface module signals.
MCF5275 Integrated Microprocessor Family Hardware Specification, Rev. 1.1
UnCTS
UnRTS
USB_CLK
USB_SPEED Applications which make use of low speed USB signalling must be
USB_RN
USB_RP
USB_RXD
USB_SUSP
USB_TN
Abbreviation
Abbreviation
Table 12. UART Module Signals (continued)
Input data from the differential input receiver. USB_RXD is the
This 48MHz (or 6MHz) clock is used by the USB module for both
clock recovery and generation of a 12Mhz (or 1.5MHz) internal bit
clock.
able to switch the USB transceiver between low speed and full speed
operations. Software has control of this function by driving the state
of the USB_SPD bit in the USB_CTRL register onto the
USB_SPEED pin.
This signal is one half of the differential USB signal, and is extracted
from the USB cable via a single ended input buffer on the analog
front end. This signal is used by the module for detecting the single
ended 0 (SE0) USB bus state.
This signal is one half of the differential USB signal, and is extracted
from the USB cable via a single ended input buffer on the analog
front end. This signal is used by the module for detecting the single
ended 0 (SE0) USB bus state.
single-ended data extracted from the USB_RP and USB_RN signals
via a differential input buffer.
After a long period of inactivity (3.0ms minimum), the USB will enter
suspend mode, indicated on the interface by an active state on
USB_SUSP. During this mode, the device is supposed to enter a low
power state while waiting for a wake-up from the USB Host. When
the device enters suspend mode, it asserts the suspend signal which
forces the analog front end into a low power state. When the device
leaves suspend mode, USB_SUSP is deasserted, enabling the
analog front end for normal USB operations.
This signal is one half of the differential NRZI formatted output from
the USB module. It is fed to the transmitted D- input of the analog
front end.
Table 13. USB Module Signals
Indicate to the UART modules that they can begin data transmission.
Automatic request-to-send outputs from the UART modules. UnRTS
can also be configured to be asserted and negated as a function of
the RxFIFO level.
Preliminary
Function
Function
Freescale Semiconductor
I/O
I/O
O
O
I/O
I
I
I
I
O
I