You have two circuits connected by a FIFO. One circuit produ…

You have two circuits connected by a FIFO. One circuit produces at most 32 messages in any 40-cycle period of time. The other can consume up to 32 messages in that same period of time. However, the production and consumption can occur at any point within the 40-cycle window. What is the minimum FIFO depth that is guaranteed to avoid back pressure?