Trapezoid Flat Top: trapezoid flat top length (expressed in sample periods)
This is the register DPP_TRAPEZOID_FLAT_TOP (Tflattop)

Trapezoid Flat Top (0x1n60 (channel n), 0x8060 (all channels, write only), R/W, )
Sets the Trapezoid Flat Top width.
Note: the sum of the Trapezoid Rise Time (0x1n5C) and Trapezoid Flat Top should not exceed 15 us times the Decimation value for x724 
series, 8 us for x730 series.
Bit Description
[9:0] Trapezoid Flat Top duration expressed in sampling clock unit (10 ns).
[31:10] Reserved