Questions about IDT72V263

Hello All:

I am designing a data collection system for a piece of industrial equipment.  The IDT72V263 looks great for the application but I need to well understand/confirm on a couple of topics

First some details

I plan to use the chip in IDT Standard mode and not FWFT.  I don't really see an advantage of FWFT on this application. 

The basic plan is to start collecting data on a user command but once a threshold is reached (PAE goes high) the data will be Read Out at the same rate and the Write In clock thus maintaining a set amount of data. Once a trigger is active the Read Out clock will stop and the FIFO should proceed to fill up until FF is reached, This I can capture data before and after the trigger..

Question 1 - Difference between Synchronous or Asynchronus

To my eye I would use synchronous on both the write and read.  I am having a bit of an issue understanding how the 2 differ

During Asynchronous operation only the WR input is used to write data into the FIFO. Data is written on a rising edge of WR,
the WEN input should be tied to its active state, (LOW).

To my understanding the WR in this mode is essentially the same a the clock and WEN is LOW to write in both.

2 - Details on PAE

I understand that PAE is inverted but I can't find a way to put the bar on top with this editor.  Sadly Superline is not available, but I digress

I assume that PAE (PIn 66) should go LOW when the record count goes below the pre-set threshold and will go HIGH if record count increases above it, so writing in or reading out could change it's status accordingly.  Is this all correct?