trapez_shaper

Trapezoidal Shaper:

dkl(n) = v(n) - v(n-k) - v(n-l) + v(n-k-l)
p(n) = p(n-1) + dkl(n), n<=0
r(n) = p(n) + M1*dkl(n)
q(n) = r(n) + M2*dkl(n)
s(n) = s(n-1) + q(n), n<=0
M = 1/(exp(Tclk/tau) - 1) = M1/M2