Universal Serial Bus Interface
MCF5253 Reference Manual, Rev. 1
Freescale Semiconductor
24-3
The module contains a chaining direct memory access (DMA) engine that reduces the interrupt load on
the application processor, and reduces the total system bus bandwidth that must be dedicated to servicing
the USB interface requirements.
To reduce bus utilization by the USB even more, the module’s DMA does not have access to the CPU bus,
but instead accesses a dedicated memory that can be read/written by the CPU.
24.4
Modes of Operation
The module has three basic operating modes: Host, Peripheral (device), and OTG.
The mode of operation is selectable by software. In Host mode, the module supports Low, Full and High
speed USB. In Peripheral mode, only Full and High speed are supported.
24.5
External Signals
This section contains detailed descriptions of the USB interface signals.
describes the external signals functionality of the USB interface.
24.5.1
On-Chip Transceiver
The On-Chip transceiver is a UTMI+ specification compliant transceiver. It supports High, Full, and Low
speed data transmission, in both Host and Device mode. In addition, it contains all necessary circuitry for
OTG specific functionality.
Note that the USB Controller does not support Low speed operation in device mode as per USB 2.0
specification.
24.5.2
PHY Clocks
The built-in PHY has its own on-chip oscillator and PLL to generate the USB serial clocks. The oscillator
needs an external 24 MHz crystal.
Table 24-1. USB External Signals
Signal
I/O
Description
USBVBUS
AI
Internal UTMI+ transceiver—VBUS sensing input
USBID
I
Internal UTMI+ transceiver—ID pin
USBDN
I/O
Internal UTMI+ transceiver—DN
USBDP
I/O
Internal UTMI+ transceiver—DP
USB_CRIN
I
UTMI Internal transceiver oscillator input
USB_CROUT
O
Internal UTMI transceiver oscillator output
USBRES
AI
Internal UTMI transceiver—Bias current programming resistor
Summary of Contents for MCF5253
Page 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Page 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
Page 32: ...MCF5253 Reference Manual Rev 1 xxxii Freescale Semiconductor...
Page 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Page 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Page 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Page 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Page 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Page 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Page 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Page 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Page 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Page 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Page 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...