Input Rise Time: Rise time of the input signal (expressed in sample periods)
This is the register DPP_INPUT_RISE_TIME (Tirt)

Input Rise Time (0x1n58 (channel n), 0x8058 (all channels, write only), R/W, )
‐
Bit Description
[7:0] Rise Time of the Input pulse, expressed in sampling clock units (10
     ns)
[31:8] Reserved