| XC3000 | XC4000E | XC4000X | XC5200 | XC9000 | Spartan | SpartanXL | Virtex |
|---|---|---|---|---|---|---|---|
| N/A | N/A | N/A | N/A | N/A | N/A | N/A | Primitive |
LUT1_D, LUT2_D, LUT3_D, and LUT4_D are, respectively, 1-, 2-, 3-, and 4-bit look-up-tables (LUTs) with two functionally identical outputs, O and LO. The O output is a general interconnect. The LO output is used to connect to another output within the same CLB slice and to the fast connect buffer.
A mandatory INIT attribute, with an appropriate number of hexadecimal digits for the number of inputs, must be attached to the LUT to specify its function.
LUT1_D provides a look-up-table version of a buffer or inverter.
See also “LUT1, 2, 3, 4” and “LUT1_L, LUT2_L, LUT3_L, LUT4_L”.
| Inputs | Outputs | |||
|---|---|---|---|---|
| I2 | I1 | I0 | O | LO |
| 0 | 0 | 0 | INIT[0] | INIT[0] |
| 0 | 0 | 1 | INIT[1] | INIT[1] |
| 0 | 1 | 0 | INIT[2] | INIT[2] |
| 0 | 1 | 1 | INIT[3] | INIT[3] |
| 1 | 0 | 0 | INIT[4] | INIT[4] |
| 1 | 0 | 1 | INIT[5] | INIT[5] |
| 1 | 1 | 0 | INIT[6] | INIT[6] |
| 1 | 1 | 1 | INIT[7] | INIT[7] |
| INIT = binary equivalent of the hexadecimal number assigned to the INIT attribute | ||||
LUT3_D Function Table
