Computer Architecture - Question and answer - 6

26. What is a page table ?
The page table needs one entry per page. Assuming a 4GB (2^32 byte) virtual and physical address space and a page size of 4kB (2^12 bytes), we see that the the 2^32 byte address space must be split into 2^20 pages. This means the page table must have 2^20 entries. The page table can be organized in two ways namely in the R/W memory and by using associative logic. - In case of R/W memory the speed of execution of programs is slow as it requires two main memory references to read data. It is also known as memory page table.

27. What's the Interrupt Service Routine ?
Interrupt Service Routine(ISR) also called an interrupt handler  is a software process invoked by an interrupt request from a hardware device. It handles the request and sends it to the CPU, interrupting the active process. When the ISR is complete, the process is resumed.

28. What is associate mapping?
Associate mapping means that the word id bits are used to identify which word in the block is needed, but the tag becomes all of the remaining bits. This enables the placement of any word at any place in the cache memory.

29. What is direct Mapping ?
The direct mapping maps each block of main memory into only one possible cache line. or. In Direct mapping, assignee each memory block to a specific line in the cache.

30. What are the components of the Microprocessor ?
Components of this processor are ALU, Control unit, Input-output devices, and Register array. ALU (arithmetic logic unit) performs both arithmetic and logical operations.