# P-max

On NRZ waveforms, P-max is a V Max measurement on the linear fit pulse response p(k) waveform.

On PAM waveforms, the P-max measurement algorithm depends on the selected SNDR Standard:

SNDR Standard | P-max measurement algorithm
--- | ---
PCIe (PCIe 6.0), IEEE (802.3dj), ASA SG4, 5 | Effective Pmax is measured using a square root of the sum of squares of dual pulse fit vectors approach (one pulse fit on even UIs and one on odd UIs). In these cases, Effective P-max is measured on the Source waveform. See SNDR with the PCIe Gen6 Standard.
IEEE (PRBS13Q), Automatic, File | Pmax is a V Max measurement on the linear fit pulse response p(k) waveform. In these cases, P-max is measured on the Linear Fit Pulse Response waveform.

## SCPI Command

`:MEASure:SNDRatio:PMAX`