Figure 1. Differential Input Buffer Primitives
Figure 2. Differential DIFF_OUT Input Buffer Primitives
| Attribute | Values | Description |
|---|---|---|
| IOSTANDARD | See HD IOB Supported Standards | Assigns an I/O standard to the element. |
| DIFF_TERM | TRUE, FALSE | Turns the built-in differential termination on (TRUE) or off (FALSE). |
| DQS_BIAS | TRUE, FALSE | Provides pull-up/pull-down feature required for some DQS memory interface pins or provides DC bias for certain LVDS applications. |
| USE_IBUFDISABLE | FALSE | IBUFDISABLE is not supported in HD IOB and must be set to FALSE. (IBUFDS_DIFF_OUT_INTERMDISABLE and IBUFDS_INTERMDISABLE only) |
| Port | I/O | Description |
|---|---|---|
| O | Output | Buffer output representing the input path to the device. |
| OB | Output | Complimentary buffer output representing the input path to the device. (IBUFDS_DIFF_OUT, IBUFDS_DIFF_OUT_INTERMDISABLE only) |
| I | Input | Input port connection. Connect directly to top-level P-side port in the design. |
| IB | Input | Input port connection. Connect directly to top-level N-side port in the design. |
| IBUFDISABLE | Input | IBUFDISABLE is not supported in HD IOB. (IBUFDS_DIFF_OUT_INTERMDISABLE and IBUFDS_INTERMDISABLE only) |