interface performs communication between the physical device and the os.
interface performs communication between the physical device and the os.
what performs communication between the physical device and the os?
interface
the task of writing drivers thus usually falls to software engineers or computer engineers who work for hardware-development companies. this is because they have better information than most outsiders about the design of their hardware. moreover, it was traditionally considered in the hardware manufacturer's interest to guarantee that their clients can use their hardware in an optimum way. typically, the logical device driver (ldd) is written by the operating system vendor, while the physical device driver (pdd) is implemented by the device vendor. but in recent years, non-vendors have written numerous proprietary device drivers, mainly for use with free and open source operating systems. in such cases, it is important that the hardware manufacturer provides information on how the device communicates. although this information can instead be learned by reverse engineering, this is much more difficult with hardware than it is with software.
device driver
the term "doorbell interrupt" is usually a misnomer. it is similar to an interrupt, because it causes some work to be done by the device; however, the doorbell region is sometimes implemented as a polled region, sometimes the doorbell region writes through to physical device registers, and sometimes the doorbell region is hardwired directly to physical device registers. when either writing through or directly to physical device registers, this may cause a real interrupt to occur at the device's central processor unit (cpu), if it has one.
interrupt