Quatech DSC-300 User Manual

Also see for DSC-200: User manual Specifications

Quatech DSC-300 User Manual Manual pdf 15 page image

4 Address Map and Special RegistersThis chapter explains how the two UARTs and special registers are addressed, as well asthe layout of those registers. This material will be of interest to programmers writing driversoftware for the DSC-200/300.4.1 Base Address and Interrupt Level (IRQ)The base address and IRQ used by the DSC-200/300 are determined by the BIOS oroperating system. Each serial port uses 8 consecutive I/O locations. The two ports reside in asingle block of I/O space in eight-byte increments, along with a sixteen-byte reserved region, fora total of 32 contiguous bytes, as shown in Figure 7.Base Address + 8 to Base Address + 15Serial 2Base Address + 0 to Base Address + 7Serial 1I/O Address RangePortFigure 7 --- Port Address MapBoth serial ports share the same IRQ. The DSC-200/300 signals a hardware interruptwhen either port requires service. The interrupt signal is maintained until no port requiresservice. Interrupts are level-sensitive on the PCI bus.The base address and IRQ are automatically detected by the device drivers Quatechsupplies for various operating systems. For cases where no device driver is available, such as foroperation under DOS, Quatech supplies the "QTPCI" DOS software utility for manuallydetermining the resources used. See page 31 for details.Quatech DSC-200/300 User's Manual 13