User guide

C M M - 52259 J U N E 1 1 , 2 0 1 0

U S E R G U I D E

NOTE:

Do not use FB_CS0*/PQS3 in GPIO mode on Rev A boards. FB_CS0* is ded-

icated to on-board external SRAM and can not be disconnected. In GPIO

mode, driving FB_CS0*/PQS3 low will cause contention on other external bus

signals.

Mini-FlexBus chip select, FB_CS1*, is available for use with off-board external memory and

provides access to 1Mb (128k x 8) of storage space. FB_CS1* and associated address and

data lines are accessible at the BUS_PORT header. Chip select FB_CS1* is not available for

multiplexed operation.

COMMUNICATIONS

The CMM-52259 applies multiple communications ports for use in user application. Supported

communications ports include; USB, Ethernet, RS-232, and CAN. The section below provides

details on each port.

USB Port

The CMM-52259 applies a USB port supporting Host, Device, and OTG configurations. A

mini-A/B USB connector is applied supporting the different configurations. USB mode is fully

controllable by user application. The MCF52259 supports Full- and Low-Speed USB commu-

nications. The CMM-52259 is also capable of sourcing VBUS at 500 mA supporting bus-

powered USB devices.

For details on use and configuration of the USB bus refer to the Universal Serial Bus Specifica-

tion, Revision 2.0 along with the On-The-Go Supplement to the USB2.0 Specification, Revision

1.2. Both documents may be downloaded from the USB Implementer Forum at www.usb.org.

Host Mode

In Host Mode, the CMM-52259 is capable of sourcing VBUS supporting bus-powered devices.

Output current on VBUS is limited to the USB standard 500mA. The output device supplying

VBUS in host mode applications provide an over-current indicator output in the event of a fault

on VBUS. This output signal is available at TP5 located behind the USB connector.

Connecting a mini-A cable to the CMM-52259 signals the user application to configure as a

USB HOST. In this configuration, VBUS output is enabled in hardware. The user application

must disable VBUS output if required. Voltage levels on the DM and DP lines during the con-

nect sequence determine connection speed.