synchronus reset with simple respected clock.it is required more no of gates,and it is didnt have metastabilty problem.it is working is slow. 3 ?0 n1 ~6 ?8 G, o# B2 J( M: n \7 R/ q4 Q( t. j# m3 oasynchronous reset with out respected to the clock.it is required less no .of gates.it is suffer to the metastability problem.it is working is fast