38 www.xilinx.com 7 Series FPGAs SelectIO Resources User Guide
UG471 (v1.10) May 8, 2018
Chapter 1: SelectIO Resources
The IBUFDS_IBUFDISABLE primitive can disable the input buffer and force the O output
to the fabric to a logic High when the USE_IBUFDISABLE attribute is set to TRUE and the
IBUFDISABLE signal is asserted High. If USE_IBUFDISABLE is set to FALSE, this input is
ignored and should be tied to ground. This feature can be used to reduce power whenever
the I/O is idle.
IBUFDS_INTERMDISABLE
The IBUFDS_INTERMDISABLE primitive shown in Figure 1-22 is available in the HR I/O
banks and is similar to the IBUFDS_IBUFDISABLE primitive in that it has an
IBUFDISABLE port that can be used to disable the input buffer during periods that the
buffer is not being used. The IBUFDS_INTERMDISABLE primitive also has an
INTERMDISABLE port that can be used to disable the optional uncalibrated
split-termination feature. See Uncalibrated Split Termination in High-Range I/O Banks
(IN_TERM) for more details on this feature.
The IBUFDS_INTERMDISABLE primitive can disable the input buffer and force the
O output to the fabric High when the USE_IBUFDISABLE attribute is set to TRUE and the
IBUFDISABLE signal is asserted High. If USE_IBUFDISABLE is set to FALSE, the
IBUFDISABLE input is ignored and should be tied to ground. If the I/O is using the
optional uncalibrated split-termination feature (IN_TERM), this primitive disables the
termination legs whenever the INTERMDISABLE signal is asserted High. These features
can both be combined to reduce power whenever the input is idle.
IBUFDS_DIFF_OUT_INTERMDISABLE
The IBUFDS_DIFF_OUT_ INTERMDISABLE primitive shown in Figure 1-23 is available
in the HR I/O banks and is similar to the IBUFDS_IBUFDISABLE primitive in that it has an
X-Ref Target - Figure 1-2 1
Figure 1-21: Differential Input Buffer With Input Buffer Disable
(IBUFDS_IBUFDISABLE)
IBUFDS_IBUFDISABLE
IBUFDISABLE
I
IB
O
UG471_c1_65_041412
X-Ref Target - Figure 1-2 2
Figure 1-22: Differential Input Buffer With Input Buffer Disable and IN_TERM
Disable (IBUFDS_INTERMDISABLE)
IBUFDS_INTERMDISABLE
I
IB
O
UG471_c1_66_021214
IBUFDISABLE
INTERMDISABLE