The interaction between the software and the hardware must be tested. Every software has drivers. Device drivers are software designed to interface with specific hardware devices. They are stored on the hard drive and installed when the OS is first installed or when new hardware is added to a system. The OS provides some device drivers, and the manufacturer of the specific hardware device with which they are designed to interface provides others. In either case, unlike BIOS, device drivers are usually written for a particular OS and might need to be rewritten for use with another.
In addition, there are also system resources. A system resource is a tool used by either hardware or software to communicate with the other. When BIOS or a driver wants to send data to a device (such as when you save a file to the hard drive), or when the device needs attention (such as when you press a key on the keyboard), the device or software uses system resources to communicate. There are four types of system resources: memory addresses, I/O addresses, interrupt request numbers (IRQs), and direct memory access (DMA) channels.
As Table explains, all four resources are used for communication between hardware and software. Hardware devices signal the CPU for attention using an IRQ. Software addresses a device by one of its I/O addresses. Software looks at memory as a hardware device and addresses it with memory addresses, and DMA channels pass data back and forth between a hardware device and memory. All four system resources depend on certain lines on a bus on the motherboard. A bus such as the system bus has three components: the data bus carries data, the address bus communicates addresses (both memory addresses and I/O addresses), and the control bus controls communication (IRQs and DMA channels are controlled by this portion of the bus). Let’s turn our attention to a more detailed description of the four resources and how they work.
Leave a Reply
You must be logged in to post a comment.