The SLOE and SLRD are two separate input signals. But based on the application needs these may be tied together. From the timing diagrams in the datsheet,the tOEN (SLOE Turn-on to FIFO Data Valid) is always less than tSRD (setup time for SLRD) for a synchronous read. For asynchronous read, tOEN (SLOE Turn-on to FIFO Data Valid) is also always less than tXFD (SLRD to FIFO Data Output Propagation Delay). So as long as the SLOE is enable when SLRD is asserted, it should be fine and the two can be tied together for the purposes of certain applications where the external master does not have either RD# or OE# signal output control signal.