When I run the DC-DC BUCK pss simulation in virtuoso, the pss does not converge, and the error is max dU exceeded. just like this:
Conv norm = 2.57e+03, max dU(NPORT32:s7) = 3.7374 , took 5.45 s
Conv norm = 1.77e+03, max dU(NPORT32:s7) = -2.55048 , took 5.13 s

I found in spectre.out that the default setting for abstol (U) is 1 u. just like this:
Important parameter values in tstab integration:
start = 0 s
......
abstol(V) = 3 mV
abstol(I) = 1 A
abstol(U) = 1 u
.......
I want to change abstol(U) to a larger value, but I don't know where to set it. Can anyone help me? Thanks a lot!