This attribute defines the read (output) behavior of the FIFO when EMPTY. If TRUE (FWFT), the DIN data is placed on the DOUT bus before RDEN is asserted. When writing the first word to an EMPTY FIFO, the first word "falls through" to the output, and appears on the DOUT bus at the same time EMPTY is deasserted. If FALSE (standard read interface), RDEN presents the DIN data (data in the FIFO) on DOUT after the next rising edge of RDCLK. When the EMPTY flag asserts, no more data is available to be read, and any additional reads cause RDERR to assert after the next RDCLK edge. See also Operating Mode.