It seems we should repeat it 300 times for 300 cycles. I think. but I have another solution for your case: I often use a wave display tool - CosmosScope do this work. there are many function in CosmosScope that can measure different parameters.
I use the cosmosScope,too.
But I need to repeat this process for many corners,so I want to find a convinient way.
And I am in the same trouble of caculating the jitter.