All SD-FEC instances must be placed using an XDC constraint. See Required Constraints for more information. Certain placement and use guidelines are dependent on the selected SD-FEC mode. The following table shows placement options for configurations of turbo, LDPC encoder, and LDPC decoder instances; the LDPC encoder instances have no placement restrictions but the turbo and LDPC decoder placement guidelines must be followed.
The following SD-FEC configurations are supported:
- A maximum of four turbo mode SD-FEC instances can be used simultaneously.
- A maximum of eight SD-FEC instances can be used simultaneously, with up to six performing LDPC decode.
- A mixed mode of turbo decode and LDPC decode and encode is also supported up to a maximum of four SD-FEC instances. The placement guidelines for this configuration are the same as for turbo mode in the following table.
The Vivado® design tools issue an error if the combinations in the following table are not followed. See the device diagram in the following figure for reference to the SD-FEC block locations.
| Turbo Mode 1 | LDPC Mode 1 | FMAX (MHz) | |
|---|---|---|---|
| Decoder 2 | Encoder | ||
| -2 Speed Grades (Vnom Only) | |||
| X0Y7, X0Y5, X0Y3, X0Y1 | None | None | 667 |
| X0Y7, X0Y6, X0Y1, X0Y0 | |||
| None | X0Y7, X0Y6, X0Y5, X0Y2, X0Y1, X0Y0 | X0Y4, X0Y3 | 667 |
| None | |||
| None | X0Y7, X0Y6, X0Y5, X0Y4, X0Y3, X0Y2, X0Y1, X0Y0 | ||
| -1 Speed Grades (Vnom Only) | |||
| X0Y7, X0Y5, X0Y3, X0Y1 | None | None | 667 |
| X0Y7, X0Y6, X0Y1, X0Y0 | |||
| None | X0Y7, X0Y6, X0Y5, X0Y2, X0Y1, X0Y0 | X0Y4, X0Y3 | 625 |
| None | |||
| None | X0Y7, X0Y6, X0Y5, X0Y4, X0Y3, X0Y2, X0Y1, X0Y0 | ||
| All Speed Grades | |||
| X0Y7, X0Y5, X0Y3, X0Y1 | None | None | 667 |
| X0Y7, X0Y6, X0Y1, X0Y0 | |||
| None | X0Y7, X0Y6, X0Y1, X0Y0 | X0Y5, X0Y2 | 667 |
| X0Y7, X0Y5, X0Y3 X0Y1 | None | ||
| None | X0Y7, X0Y6, X0Y5, X0Y2, X0Y1, X0Y0 | ||
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