IR Communications Is Added To 50-MIPS MCU's Bag Of Tricks

Through use of a new Virtual Peripheral module, designers can use the firm's SX Series microcontrollers to incorporate an industry-standard wireless infrared communications capability into their next-generation designs. The new software module, which uses the SX MCUs as a hardware platform, implements the lower levels of the IrDA standard and the high-level IrCOMM interface protocol to provide short-range wireless communication in a variety of embedded applications. Uses range from giving portable devices, printers and PCs infrared connectivity capabilities to allowing communication with toys.The IrDA Virtual Peripheral module uses the ability of the microcontroller to rapidly re-send data upon request to eliminate the large data buffers that are typically required for such applications. It also uses the MCU's 50-MIPS performance to shape the IrDA pulses without need for external hardware. Data transfers are at speeds up to 115.2 kbps with an SX MCU running at 50 MHz. Using a 100-MHz MCU raises the rate to 1.15 Mbps.Virtual Peripheral modules are software implementations of peripheral functions that are loaded into the on-chip memory of the SX MCUs to configure them for a particular application. A complete IR communication device can be configured by loading just three Virtual Peripheral modules into the SX MCUs- the IrDA/IrCOMM protocol stack and two UARTs. One of the UARTs serves the IrDA port while the other is used with a debugging serial port. The IrDA/IrCOMM Virtual Peripheral module implements the physical layer, frame/driver layer, IrLAP layer, IrLMP layer, IAS layer and application layer of the IrDA standard. A reference design is available to assist with creating a development board for the IrDA Virtual Peripheral module. The design includes circuit diagram and bill of materials.