fpga

I need help with a FPGA problem. I want to look at 48 DIO's and everytime there is a change I want to record the I/O state and time. This can happen over a period of 10 seconds or so. the duration between changes can be in milliseconds. I attached the code I am starting with. The plan was to form a single 64 bit word from the 48 DIO and everytime the word changed an entry is made to block memory. Unfortunately I don't fully understand the block memory process.

Can someone show me the proper way to write too, (and ultimately read from) the block memory? Is there a better way to do what I'm trying to do?

My hardware is an NI9082 and PC.

Thanks

John Mittleider

Boeing