1.2.1 IBIS-AMI
(Ask a Question)This section describes the IBIS-AMI Rx model parameters that need to be varied in order to obtain proper tuning of the receiver. In Rx model, AMI tab contains four important parameters used for receiver optimization. The following table lists the four key parameters.
| Rx Variable | Description |
|---|---|
| RXTERM | Rx Termination. It supports 85Ω, 100Ω and 150Ω |
| CTLE_ID | This parameter changes the CTLE Settings. Total 63 settings are provided.For more information of the complete 63 settings, see Table 1-5. |
| DFE_MODE | Determine the DFE Calibration mode. 1 = off 2 = fixed 3 = adapt Adapt mode does auto calibration of the device to obtain the best DFE coefficients where as in fixed mode coefficients are added manually. |
| DFE_TAP | 5 Tap DFE is used. You can manually edit each tap in DFE_MODE = 2 or DFE_MODE = 3. In DFE_MODE = 3 the tool takes the value provided in DFE_TAP as initial values to obtain the optimized DFE coefficients. |
DFE, when used in adapt mode, calibrates the receiver and gives the best DFE coefficients. These coefficients are then used in the fixed mode in simulation to view the proper eye. Each DFE coefficient in Libero SoC corresponds to 6m in IBIS-AMI DFE tap (tap 1 to tap 5). The following table lists the mapping of the coefficients.
| IBIS AMI Value | Libero® Value (Hex) | IBIS AMI Value | Libero Value (Hex) |
|---|---|---|---|
| 0.006 | –1 | –0.006 | 1 |
| 0.012 | –2 | –0.012 | 2 |
| 0.018 | –3 | –0.018 | 3 |
| 0.024 | –4 | –0.024 | 4 |
| 0.03 | –5 | –0.03 | 5 |
| 0.036 | –6 | –0.036 | 6 |
| 0.042 | –7 | –0.042 | 7 |
| 0.048 | –8 | –0.048 | 8 |
| 0.054 | –9 | –0.054 | 9 |
| 0.06 | –a | –0 .06 | a |
| 0.066 | –b | –0.066 | b |
| 0.72 | –c | –0.72 | c |
| 0.78 | –d | –0.78 | d |
| 0.084 | –e | –0.084 | e |
| 0.09 | –f | –0.09 | f |