Across
- 4. this is a register used to contain the instruction which is currently being executed or decoded.
- 5. a high speed auxiliary memory which permits high speed data transfer and retrieval.
- 6. mode of addressing in which the contents of the memory location in the operand are used; same as absolute addressing.
- 8. short for operation code, the part of a machine code instruction that identifies the action the CPU will perform.
- 11. a number that is used with the logical operators AND, OR or XOR to identify, remove or set a single bit or group of bits in an address or register.
- 12. the result of carrying out a calculation which produces a value too large for the computer’s allocated word size.
- 13. the bus that allows data to be carried from processor to memory (and vice versa) or to and from input/output devices.
- 17. temporary general purpose register which stores numerical values at any part of a given operation.
- 18. the bus that carries signals from control unit to all other computer components.
- 21. function allowing a computer to process more than one task/process at a time.
- 24. 3rd part of the FDE cycle
- 26. bus that carries the addresses throughout the computer system.
- 28. mode of addressing in which the contents of the contents of the memory location in the operand are used.
- 30. a computer program that translates programming code written in assembly language into machine code; assemblers can be one pass or two pass.
- 31. signal sent from a device or software to a processor requesting its attention; the processor suspends all operations until the interrupt has been serviced.
Down
- 1. a register used in a computer to store the address of the instruction which is currently being executed.
- 2. a deliberate pause in the execution of a program during testing so that the contents of variables, registers, and so on can be inspected to aid debugging.
- 3. the code language that the CPU uses.
- 7. A line on the contreol bus that controls speeed of the CPU
- 9. a number given to an interrupt so the processor knows which need to be serviced first .
- 10. the unit that ensures synchronisation of data flow and programs throughout the computer by sending out control signals along the control bus.
- 13. core a CPU containing two cores.
- 14. data structure used to implement an interrupt vector table.
- 15. mode of addressing in which the value of the operand only is used.
- 16. high speed memory external to processor which stores data which the processor will need again.
- 19. component in the processor which carries out all arithmetic and logical operations.
- 20. holds all data and programs needed to be accessed by the control unit.
- 22. mode of addressing in which the contents of the memory location found by adding the contents of the index register (IR) to the address of the memory location in the operand are used.
- 23. the part of a machine code instruction that identifies the data to be used by the CPU.
- 25. software which handles interrupt requests (such as ‘printer out of paper’) and sends the request to the CPU for processing.
- 26. a low-level chip/machine specific programming language that uses mnemonics.
- 27. value given to interrupts based on values 0 to 31.
- 29. a unit made up of ALU, control unit and registers which is part of a CPU; a CPU may contain a number of cores.