.param VSup = 1.0V

VCK  nCK  0 Pulse (0 Vsup 1n 10p 10p 0.99n 2n)
VCKb nCKb 0 Pulse (Vsup 0 1n 10p 10p 0.99n 2n)
VD nD 0 PWL 0p 0 2n 0 2.01n Vsup 4n Vsup 4.01n 0 6n 0 6.01n Vsup