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The Little Board P6d IrDA interface supports both SIR (Serial Infrared) and FIR (Fast Infrared) standards . The SIR standard allows serial communication at baud rates up to 115K Baud. The FIR standard allows data rates up to 4Mbps. Requirements for an IrDA Interface On the Little Board P6d module, the IrDA physical link hardware consists of an IR transmit encoder and IR receiver decoder. To implement an IrDA port, the OEM must supply an IR transducer, which consists of the output driver and IR emitter for transmitting, and the receiver IR detector. Particular IR transducers may require additional external components. The IrDA port uses the second serial port to drive its internal encoder/decoder. When using the IrDA interface, you cannot use serial 2 as an RS232, RS485, or RS422 port. IrDA Connector (Part of Utility J19) There are two popular implementations of Fast IR. One uses a separate receive line capable of receiving at the higher data rate (up to 4 Mbytes/second). The other is implemented with a mode control line. When the IR port is set for high speed, the mode select line (IRMODE) is high. This switches the external transceiver to high speed mode. The IrDA port pinout is listed in Table 2-18. Little Board P6d Module Table 2-18. IrDA Interface Pinout J19 Pin # Signal Name Function 18 IRMODE /IRRXB Fast IR Receive/Mode Input 19 IRTX IR Transmit 20 IRRXA IR Receive (SIR) Multi-Mode Parallel Port The Little Board P6d system incorporates a multi-mode parallel port. This port supports four modes of operation: • Standard PC/AT printer port (output only) • PS/2-compatible bidirectional parallel port (SPP) • Enhanced Parallel Port (EPP) • Extended Capabilities Port (ECP) This section lists the pinout of the parallel port connector and describes how to configure it for its I/O port and interrupt assignments, how to assign a DMA channel to the port when operating in ECP mode. And programming information, including how to use the port for bidirectional I/O. I/O Addresses and Interrupts The parallel port functions are controlled by eight I/O ports and their associated register and control functionality. The Little Board P6d parallel port is assigned to the primary parallel port address normally assigned to LPT1 and cannot be changed. You may disable the port in Setup to free the hardware resources for other peripherals. The parallel port can be configured to generate an interrupt request upon a variety of conditions, depending on the mode the port is in. Assignment of an interrupt to the parallel port is optional, and its use depends on software requirements and which mode of operation you are using. IRQ 7 is the default parallel port IRQ assignment. Table 2-19 lists the parallel port addresses and IRQs. Table 2-19. Parallel Printer I/O Addresses and Interrupt Selection I/O Address Interrupt Primary 378h - 37Fh 7 Secondary 278h - 27Fh 5 Secondary 3BCh - 3BFh 7 Disable None None ROM-BIOS Installation of Parallel Ports Normally, the BIOS assigns the name LPT1 to the primary parallel port, and LPT2 to the secondary parallel port (if present), and so on. However, the BIOS scans the standard addresses for parallel ports and if it only finds a secondary port, it assigns LPT1 to that one. Therefore, if the Little Board’s parallel port is enabled, it will be assigned LPT1 by the BIOS. If it is disabled and there is another parallel port in your system, that port will be assigned LPT1 by the BIOS. The ROM-BIOS scans I/O addresses for parallel ports in the following order: 3BCh, 378h, 278h. DMA Channels In ECP enhancement mode, the parallel port can send and receive data under control of an onboard DMA controller. On the Little Board P6d module, select a DMA channel in Setup. You can configure the parallel port to use either DMA channel 1 or DMA channel 3. If you will not be using DMA with the parallel port, leave it disabled. This makes the DMA channel available to other peripherals installed on the expansion buses. Parallel Port Connector (J9) The parallel port appears on J9. Its pinout is arranged so that a 26-pin ribbon cable can be directly connected to a 25-pin DB-25 connector to match the PC standard pinout. Table 2-20 gives the connector pinout and signal definitions for the parallel port. In addition, the table indicates the pins to which each signal must be wired for compatibility with a standard DB25 connector. Normally the PC parallel port uses a female “DB“ connector. Little Board P6d Module Table 2-20. Parallel Port Connections (J9) Pin # Signal Name Function In/Out DB25 Pin 1 STB* Output Data Strobe Out 1 3 PD 0 LSB Of Printer Data I/O 2 5 PD 1 Printer Data 1 I/O 3 7 PD 2 Printer Data 2 I/O 4 9 PD 3 Printer Data 3 I/O 5 11 PD 4 Printer Data 4 I/O 6 13 PD 5 Printer Data 5 I/O 7 15 PD 6 Printer Data 6 I/O 8 17 PD 7 MSB Of Printer Data I/O 9 19 ACK* Character Accepted In 10 21 BUSY Cannot Receive Data In 11 23 PE Out of Paper In 12 25 SLCT Printer Selected In 13 2 AUTOFD* Autofeed Out 14 4 ERROR Printer Error...