1) When two or more components need to exchange data, Cache is very useful. Cache provides a small buffer to transmission problems, the data must be consistent in Cache, that if a member changes its content, cache backup must be updated in time. cache the price is more expensive, because fast storage are often more expensive.
2) An interrupt is a hardware-generated change of flow within the system. An interrupt handler is called to deal with the cause of the interrupt; control is then returned to the interrupted context and instruction. A trap is a software-generated interrupt. A trap can be generated intentionally by a user program. It can be used to call operating system routines or to catch arithmetic errors.
3) CPU: is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions. Traditionally, the term CPU refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry.
A device controller: is a part of a computer system that makes sense of the signals going to, and coming from the CPU. There are many device controllers in a computer system. Any device connected to the computer is connected by a plug and socket, and the socket is connected to a device controller. Device controllers use binary and digital codes. Each device controller has a local buffer and a command register. It communicates with the CPU by interrupts. A device's controller plays an important role in the operation of that device; it functions as a bridge between the device and the operating system.
4) An interrupt handler, also known as an interrupt service routine or ISR, is a callback function in microcontroller firmware, an operating system or a device driver, whose execution is triggered by the reception of an interrupt. In general, interrupts and their handlers are used to handle high-priority conditions that require the interruption of the current code the processor is executing.