Cache Implementation (Fall, 2018)

 Computer Architecture
   Prof. HyungJune Lee

http://eureka.ewha.ac.kr/eureka/hs/hssg4005q.do?YEAR=2018&TERM_CD=20&GROUP_CD=20&SUBJECT_CD=20493&CLASS_NUM=02

3. Overall Flow

 First, in main(), initialize memory and cache using init_memory_content() and init_cache_content().

Read address and data type from input file ‘accessed_input.txt’ line by line while input file pointer does not meet EOF(end of file).

After read data from input file, global_timestamp increase at each line read.

Get data from cache or memory with retrieve_data(). retrieve_data() needs 2 arguments, void pointer type addr and character type data_type.

main() pass addr and data type that reads from input file. 

In retrieve_data(), get accessed_data by invoking check_cache_data_hit().

check_cache_data_hit() needs 2 arguments same as retrieve_data(). retrieve_data() pass 2 arguments received from main() to check_cache_data_hit(). 

In check_cache_data_hit(), if it can access data using cache return that accessed data to retrieve_data() and increase num_cach_hits.

If not, return -1 so retrieve_data() invoke access_memory().

After invoking check_cache_data_hit(), if value_returned is -1, it means cache miss, so invoke access_memory().

access_memory() needs 2 arguments same with check_cache_data_hit(). 

In access_memory(), increase num_cache_memory and invoke find_entry_index_in_set() to find entry index.

Using entry index that found by find_entry_index_set(), save data into cache from memory. And return the data to retrieve_data(). 

Increase num_bytes according to data_type to calculate bandwidth. Finally, returned the accessed_data to main().

If there are errors in access memory, -1 will be returned.

Print the accessed data received by retrieve_data() and accessed_addr, accessed_data type to an output file every time accessed.

After finish reading the input file, print the hit ratio and bandwidth.