Cache Modelling & Simulator

mesi_cache_quad_core_bus_arbit_memory_ctrl__2.py

0.00MB

 

 

 

 

Here's a detailed guide designed for university students who are new to SoC, explaining how to use a multicore cache behavior simulator. This guide includes the simulation's purpose, detailed technical descriptions of each component, how to run the code, and how to analyze the results.

 

1. Purpose of the Simulator
This simulator is a tool for understanding cache operations and bus arbitration algorithms in multicore processors. Each core manages its own cache and processes memory access requests through a bus. The simulation allows you to observe firsthand how cache coherence is maintained and how data synchronization issues are handled in a multicore environment.

2. Simulation Component Descriptions
  (1) CacheLine Class
-Purpose: Models an individual cache line within the cache system. A cache line is the basic unit for storing blocks of data in memory.
-Attributes:
  -`state`: Indicates the current state of the cache line.

               Possible states include `Invalid`, `Shared`, `Exclusive`, and `Modified`.
  - `data`: Represents the actual data stored in the cache line.

  (2) Bus Class
-Purpose: Models the role of a bus that mediates data transfers between the CPU and memory. In multicore systems, the bus is a critical component for managing cache coherence and data synchronization.
-Methods:
  -`broadcast(sender, address, action)`: Alerts other CPUs when a particular CPU requests data, facilitating appropriate actions to maintain coherence.

 (3) BusArbitrator Class
- Purpose: Ensures fair bus access across multiple cores in a multicore system.
- Functionality: Uses a round-robin algorithm to sequentially allocate bus access to each CPU.

 (4) CPU Class
- Purpose: Represents each core in a multicore processor. Operates as a separate thread, independently simulating memory access requests.
- Methods:
  - `run()`: Main execution function of the CPU thread, simulating various memory access requests.
  - `access_memory(address, mode)`: Handles cache hits or misses based on the given address.

3. How to Run the Code
1. Install Python: Ensure Python is installed on your system.
2. Create Code File: Save the above code as `cache_simulation.py`.
3. Execute Code: Run the script by typing `python cache_simulation.py` in the terminal.
4. Check Log Files: After execution, review the log file generated. The log file is saved in the same directory as the script with the format `cache_simulation_YYYY-MM-DD_HH-MM-SS.log`.

4. How to Analyze Results
- Log File Analysis: Check each CPU's cache hits, misses, snooping events, and clock cycles in the log file.
-Performance Metrics: Calculate the total clock cycles and average latency for each CPU from the logs to assess the overall system performance.

This guide aims to provide students with a deeper understanding of the complexities of multicore systems and cache management, bridging theoretical knowledge with practical operation to enhance the learning experience.