I want to check positive level of clock at every clock cycle until stop condition.
So,in i2c suppose the positive level of scl(serial clock) is 4000ns, i want to check and compare this time unit until my stop condition is detected,
i tried until,until_with and throughout but it is not working for me.
Consider using fork join_any and flags.
For example (not your issue, but an example of the methodology). However do read my paper as it addresses more on the methodology,
// b==0 as long as "a==1"
always @(posedge a) begin
bit ahappen;
assert (! b);
fork
@(posedge b) ahappen=1'b1;
@(negedge a) ;
join_any
assert (ahappen=1'b0);
end