Associative MemoryThe word of information stored in Ram & Rom identified by its address location. The memory access time depend on location of information.There are many algorithms develop to minimize the access time.Searching of an item by its content rather than address can reduce access time.Such kind of memory where search based on content of memory than address this type of memory known as associative memory& content addressable memory.In this memory input like word to word stored in memory and give resultant output.

Type of memoryThere are two types of memory.Auto- associative memoryHetero- associative memory In auto- associative memory gives matching result of by comparing current input pattern and pattern stored in memory. In hetero-associative memory gives unmatched result by comparing current input pattern and pattern stored in memory.

Explained with following procedure.1.Suppose an associative memory contain number of words with n bit per word.A words looks like . 101001002. The content of argument resister (A) are compared with the content in memory.3. Key register work as mask register. It consist of n number of bits. The 1 bit in this register show the bit position in argument resister to be matched with bit position in associative memory.

For example Argument resister (A)

Key resister (K) 101010100100

Read write operation on associative memory. Transfer of information from memory word to outside environment called read operation and transfer to outside environment to be stored in memory called write operation.Write operation on associative memory It has two memory cycle to write data. first cycleWrite in one binary circuit of address storage cellSecond write in binary circuit of address cell.Read operation on associative If more than one word in memory match with word in argument register, match word read in sequence by apply read signal.