F453 State Flashcards
State three of the tasks performed by an assembler when producing machine code.
Reserves storage for instructions and data.
Replaces mnemonic op codes by machine codes.
Replaces symbolic addresses by numeric addresses.
Creates a symbol table to match labels to addresses.
Checks syntax/offers diagnostic for errors.
State two features of a compiler.
Translates the whole program as a unit.
Creates an executable program/intermediate program.
Report a number of errors at the same time.
Optimisation.
State the three stages, in order, of the machine cycle in classic Von Neumann Architecture.
Fetch-Decode-Execute.
State the type of traversal that should be used to obtain the reverse Polish form from a binary tree.
Post Order Traversal (POT).
State what data structure, other than a binary tree, may be associated with reverse Polish notation.
Stack.
State a symbol, often associated in mathematical expressions, that is not required when working with reverse Polish notation.
Parenthesis.
State the meaning of the term symbolic addressing.
The use of characters that represent the address of a store location.
State the meaning of direct addressing.
The instruction gives the address to be used.
State two sources of interrupts and explain why these interrupts have different priorities.
Power failure - higher priority.
User interrupt.e.g. new user log on request.
The reason is that a new user can wait but the data that needs to be saved before the power failure.
State two reasons why memory management is necessary.
To allocate memory to allow separate processes to run at the same time.
To deal with allocation when paging/segmentation.
To reallocate memory when necessary.
To protect processes/data from each other.
To protect the operating system/provide security.
To enable memory to be shared.
State why virtual memory may be needed.
To allow programs to run that need more memory than is available.
State what software is required to run intermediate code.
Interpreter/virtual machine.
State one disadvantage of using intermediate code.
The program runs more slowly.
It has to be translated each time it is run.
It needs additional software.
State the two features of the Von Neumann Architecture.
Single control unit/processor.
Programs stored with data in the same format processed one instruction at a time.
A: 1001 | 0110
B: 0011 | 1010
State which of these numbers have been normalised giving a reason for your answer.
A
The first two bits are different (start with 10) whereas B starts with 00.
State the meaning of a static data structure.
Size is fixed when a structure is created/size can not change during processing.
State one advantage of using a static data structure over a dynamic data structure.
Amount of storage is known/easier to program.
State what data structure is used when procedures are called during program execution.
Stack.
State two ways in which paging and segmentation are similar.
Both are ways of partitioning memory.
Both are in the backing store/virtual memory.
State one difference between paging and segmentation.
Segments are different sizes but pages are fixed in size.
Segments are complete sections of programs but pages are made to fit sections of memory.
Segments are logical divisions but paging are physical divisions.
State the format of the mantissa of a normalised floating point binary number.
Exponent is adjusted so that the mantissa starts with 01 or 10.
