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Signal Descriptions
2-18
Freescale Semiconductor
2.3.15
Universal Serial Bus (USB) Signals
2.3.16
UART Module Signals
describes the signals of the three UART modules, where
n
equals 0 – 2. Baud-rate clock inputs
are not supported.
Table 2-17. USB Module Signals
Signal Name
Abbreviation
Function
I/O
USB D-
USB_DM
D- output of the dual-speed transceiver for the On-the-Go module.
O
USB D+
USB_DP
D+ output of the dual-speed transceiver for the On-the-Go module.
O
USB VBUS Enable
USB_VBUS_EN
Enables the off-chip VBUS charge pump when USB OTG module is
configured as a host.
O
USB VBUS over-current USB_VBUS_OC
Indicates to the processor that a short has occurred on USB data
bus.
I
USB External Pull-up
Enable
USB_PULLUP
Either use this pullup enable output signal, or turn it off in the CCM’s
MISCCR[USBPUE] bit. If internal pullup (and not this output signal)
is used, the internal pullup automatically switches impedances
based on whether USB is transmitting or receiving.
O
ULPI Data Bus
ULPI_DATA[7:0]
These bi-directional signals are ULPI data bus. Synchronous to
USB_CLKIN.
I/O
ULPI Next Data
ULPI_NXT
This input is the ULPI next data. Synchronous to USB_CLKIN.
I
ULPI Stop Data
ULPI_STP
This output is the ULPI stop data. Synchronous to USB_CLKIN.
O
ULPI Data Bus
Direction
ULPI_DIR
This input is the ULPI data bus direction. Synchronous to
USB_CLKIN.
I
Table 2-18. UART Module Signals
Signal Name
Abbreviation
Function
I/O
Transmit Serial Data
Output
U
n
TXD
Data is shifted out lsb first at the falling edge of the serial clock source.
Output is held high when transmitter is disabled, idle, or in local
loopback mode.
O
Receive Serial Data
Input
U
n
RXD
Data is sampled Isb first at the serial clock source’s rising edge. When
the UART clock is stopped for power-down mode, any transition on this
pin restarts it.
I
Clear-to-Send
U
n
CTS
Indicates UART modules can begin data transmission
I
Request-to-Send
U
n
RTS
Automatic request-to-send outputs from UART modules. They may
also be asserted and negated as a function of the received FIFO level.
O
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...