RapidIO: The Next Generation Communication Fabric For Embedded Application

14.3. SUPPORTING FUNCTIONS

14.3.1. RapidIO Controller Configuration

Most systems require both 'out-of-band' and 'In-band' configuration capabilities. Out-of-band configuration implies that the devices can be configured using other signaling or protocols beyond the mechanism provided within the RapidIO protocol. Conversely, in-band configuration relies solely on the mechanisms provided by the RapidIO protocol. In either case, it is desirable that all device configuration registers be accessible by either out-of-band or in-band signaling.

There are many standard approaches that can be used for out-of-band configuration of RapidIO devices. Two examples are:

• I2C Interface: the I2C Interface is commonly used on many device types and can be used for initializing internal end point registers after reset. The I2C interface can also be used to provide a method for performing random access master read and write operations to EEPROMs or to other I2C compatible slave devices. I2C is an acronym for intelligent I/O controller. It is an industry standard for a low-pin-count serial interface for device initialization and control.

• JTAG Interface: a RapidIO end point can also include a JTAG interface as an out-of-band configuration method. The JTAG interface would have the ability to access and configure the internal end point registers. Register access through JTAG can also be used during normal operation to perform extensive read and write accesses on the performance registers, without slowing ...