The latency of the transceiver rx_syncstatus signal de-asserting after the assertion of the rx_enapatternalign signal in Stratix® IV GX/T, Arria® II GX/Z and Cyclone® IV GX devices is dependent upon the implemented Rx PCS datapath.
The Word Aligner block is the first block in the PCS datapath. The rx_enapatternalign signal is an asynchronous input to the Word Aligner block. The rx_syncstatus signal is a synchronous output from the Word Aligner block and has the same latency as the Rx PCS datapath. Therefore the latency of the rx_syncstatus de-asserting after the assertion of the rx_enapatternalign signal is equal to the PCS datapath latency from the Word Aligner.
Diagrams implying the latency to be one rx_clkout clock cycle in the Stratix IV GX/T, Arria II GX/Z and Cyclone IV GX device handbooks will be updated in due course.