UltraScale Architecture SelectIO Resources User Guide (UG571)

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1.14 English

The IOBUFDS_DIFF_OUT_INTERMDISABLE primitive (shown in This Figure) is available in the HR I/O banks. The IOBUFDS_DIFF_OUT_INTERMDISABLE primitive has an INTERMDISABLE port that can be used to disable the optional on-die receiver termination feature. See Uncalibrated Input Termination in I/O Banks for more details on this feature. TM and TS must be connected to the same input (T) from the interconnect logic for this primitive to have the expected behavior that is specific to the UltraScale architecture.

Figure 1-39:      Differential Bidirectional Buffer with Complementary Outputs, Input Buffer Disable, and On-Die Input Termination Disable (IOBUFDS_DIFF_OUT_INTERMDISABLE)

X-Ref Target - Figure 1-39


If the I/O is using the on-die receiver termination features, this primitive disables the termination legs whenever the INTERMDISABLE signal is asserted High and the output buffer is 3-stated. When the output buffer is 3-stated (T = High), any on-die receiver termination is controlled by INTERMDISABLE. When the output buffer is not 3-stated (T = Low), the input buffer and on-die receiver termination are disabled and the O output (to the internal logic) is forced to a logic-Low.


TIP:   The IBUFDISABLE feature is not supported with this primitive in the UltraScale architecture.