Multipurpose Counters

Counters in the memory module count the occurrence of events that can provide software with an indication of how memory is being utilized. One usage of such information would be for software to recognize bottlenecks by measuring depths of the memory FIFOs. As another example, if the monitor shows a large number of invalidates at a memory location, then this might indicate that false sharing is occurring. The following are examples of events that can be counted:

• total number of transactions to memory module
• number of transactions of a specific type (e.g., read request, write request, write, etc.)
• number of invalidates sent out of memory module
• depth of incoming and outgoing FIFOs