Irsim output for 8-bit ripple carry adder
Spice Analysis of:
1111 1111 + 1111 1111 + 1 = 1 1111 1111
1111 1111 + 0000 0000 + 1 = 1 0000 0000
Both Spice graphs demonstrate the propagation delay of the carry. It takes about 8 ns for the adder to stabalize.