SNLA236 September 2015 DS125BR111 , DS125BR401A , DS125BR820
2.1 Default Transmit Equalization Coefficients
SAS-3 defines a pair of Reference waveforms, Reference 1 (left side) and Reference 2 (right side). In many cases Reference 1 is used as a starting point for link training.
Figure 2. Typical Host Transmitter Reference Waveforms The voltage specifications for Reference 1 and Reference 2 waveforms are listed in Table 2.
Table 2. SAS-3 Reference Waveform Characteristics
| WAVEFORM | Va | Vb | Vc | Vd | Va/Vb | Vc/Vb | POST CURSOR | PRE CURSOR |
|---|---|---|---|---|---|---|---|---|
| Reference 1 | 1.03 | 0.725 | 0.915 | 1.20 | 1.42 | 1.262 | -3 dB | 2 dB |
| Reference 2 | 0.84 | 0.23 | 0.61 | 1.20 | 3.65 | 2.652 | -11.2 dB | 8.5 dB |
| No Tx Eq | 1.20 | 1.20 | 1.20 | 1.20 | 1 | 1 | 0 dB | 0 dB |