The later has memory and former doesn’t, so in an advent effort to incorporate memory into a combinational circuit brought in the concept of Finite state machine serial adder. If you have any query/suggestion please feel free to comment below the post.Abstract- Logic design is in itself bifurcated to- Combinational and Sequential circuits. We got the following schematic after mapping the hdl code to the standard library. #10 a= 16'b1111111111111111 b=16'b000000000000000 cin=1'b1 ġ6 bit Ripple Carry Adder Simulation Results:Ĭadence RTL compiler is used to synthesize the verilog code with Uofu standard library. We are here providing the testbench for 16-bit Ripple Carry Adder `timescale 1ns / 1ps Module ripple_carry_4_bit(a, b, cin, sum, cout) įull_adder fa0(.a(a). Module ripple_carry_16_bit(a, b, cin,sum, cout) The Verilog Code for 16-bit Ripple Carry is given below- `timescale 1ns / 1ps Similar way, we can get N-bit ripple carry adder.

Now, by using this 4-bit ripple carry adder 16-bit ripple carry adder Verilog code has been written. From this, we can get the 4-bit ripple carry adder. First the Verilog code for 1-bit full adder is written. While writing the Verilog code for 16-bit Ripple carry adder the same procedure is used. Now as we have 4-bit ripple carry adder so it can further be cascaded in series to get higher bit adder.įor example, we can get 16 -bit Ripple Carry Adder by cascading in series four 4-bit ripple carry adders. The out carry bit of every full adder is fed to the input of the next full adder. The boolean equation for 1 bit full adder output, S0 and C1, is given byĪ 4-bit Ripple Carry adder is built by cascading four 1-bit full adders in series. Where S0= LSB sum bit and C1=Carry Out of first 1-bit full adder Here we can see the LSB bits are A0, B0 and C0 where C0 is the input carry bit. The general structure of 4-bit ripple carry adder is shown below. In ripple carry adder the carry bit may ripple from first bit to last bit. Ripple carry adder is the basic adder architecture.

Fsm serial adder vhdl