04-05-2018 01:28 AM
What delay element is used for phase shift when attribute OUTPUT_PHASE_90 = true?
04-05-2018 01:39 AM
The OUTPUT_PHASE_90 is done via the quarter delays which is a part of the Step 2 of the BSC calibration
From UG 571
"This step walks through the input and/or output delay of each used bit slice to calculate the number of taps required to provide the delay requested by DELAY_VALUE attribute. These calculated delay taps are stored in the RIU registers (ODELAYxx and IDELAYxx).The same is done for the BITSLICE_CONTROL available quarter delay lines (PQTR/NQTR) to provide the 90-degree equivalent delay when RX_CLK_PHASE_P(N) = SHIFT_90. These
values are stored in the RIU PQTR and NQTR registers."