AN2645 Freescale Semiconductor / Motorola, AN2645 Datasheet - Page 3

• Manufacturer Part Number: AN2645
• Description: Interfacing the Philips ISP1362 USB OTG Controller to the MCF5249
• Manufacturer: Freescale Semiconductor / Motorola

1.1
The MCF5249 is a 32-bit embedded processor based on the V2 ColdFire core. The MCF5249 is an excellent
general-purpose system controller with over 125 Dhrystone MIPS at 140 MHz performance. On-chip
peripherals include an enhanced Multiply Accumulate Controller (eMAC), SmartMedia interface, 12-bit
ADC, and a Flash memory card interface. In addition, the MCF5249 also features the peripheral set standard
on all ColdFire microprocessors including the System Integration Module (SIM), DMA, dual UART, QSPI,
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Additional features that make this processor attractive to customers designing portable applications are the
1.8-V core power supply which provides low-current consumption ideal for battery operated devices and
96 Kbyte on-chip SRAM. The on-chip SRAM features power management such that power dissipation can
be decreased depending on how the user utilizes the memory space.
The MCF5249 also features serial audio peripherals (I
MCF5249 was designed for portable applications, it is the ideal processor to interface to the USB OTG
standard.
Finally, most USB controllers available today have a 16-bit data bus. The MCF5249 and the Philips
ISP1362 both have a 16-bit external bus making the interface between the two slightly less complicated.
1.2
The ISP1362 is a single-chip USB OTG controller compliant with the On-The-Go Supplement to the USB
2.0 Specification Rev 1.0. The host and device controllers are compliant with Universal Serial Bus
Specification Rev 2.0, supporting data transfer rates of both full speed (12 Mbps) and low speed (1.5 Mbps).
As mentioned above, the ISP1362 has two ports. For the purpose of this design, port 1 is hardware
configured to operate in either device or OTG mode. Port 2 is hardware configured to operate in host mode.
The OTG port can switch roles from host to device or from device to host through the host negotiation
protocol (HNP) as specified in the OTG supplement.
The ISP1362 features a software-controlled connection to the USB bus called SoftConnect which is used
when port 1 is operating in device mode. SoftConnect replaces the requirement for an external 1.5-K pull-up
resistor connected to the D+ signal to indicate a physical connection to the USB bus. Alternatively, an
external pull-up can be used, but for this design SoftConnect is enabled.
The ISP1362 has internal 15-K pull-down resistors for the host controller eliminating the need to add these
externally. It also has internal 15-K pull-down and 1.5-K pull-up resistors on the OTG D+ and D– signals,
eliminating the need to add these externally. In this design, all internal resistors should be enabled.
The ISP1362 also features a good USB connection indicator, called GoodLink, that blinks with USB traffic.
This is also implemented on the daughter card design.
The USB host supports all four types of data transfer: control, bulk, interrupt, and isochronous.
The USB device supports 2 control endpoints and up to 14 configurable endpoints, which can be
programmed to any of the 4 transfer types.
MOTOROLA
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, general-purpose timers, and the real-time BDM (Background Debug Interface) interface.
MCF5249 ColdFire Microprocessor
Philips ISP1362 USB OTG Controller
Interfacing the Philips ISP1362 USB OTG to the MCF5249
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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) designed for portable MP3 CD players. As the
Design Overview
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