Verilog Code For Serial Adder Data
The problem statement, all variables and given/known data My homework is to design a Serial Adder in Verilog using a shift register module, a full adder module.
Lab2 LAB 2: Sequential logic in VHDL Bit serial adder: The above block diagram describes a digital design that demonstrates bit-serial arithmetic. Two 4-bit parallel inputs are converted to 4-bit serial bit streams with least significant bit (LSB) first. A full-adder sums the two numbers on bit at a time, carrying-in the carry bit from the previous clock cycle. Finally the output serial bitstream is converted back into a parallel sum. To build this circuit, several separate components must be created and verified in simulation. Shift Register: You need to produce a dual-purpose shift register that can:.
Verilog Code For Serial Adder
Receive a 4-bit parallel value and convert it to a serial bitstream, or. Receive a 4-bit serial bitstream and convert it to a parallel output.
Serial data is clocked into the shift register from input port serin. The shift register component holds four bits of data at a time. If shiftin is set to 0, the data bit from serin is put in the top bit of the register (most significant bit), and the other three bits are shifted down by one position. The contents of the bottom-most bit in the register is sent to output port serout. If the shiftin signal is set to 1, the four bits of parallel input data are loaded from parin into the 4-bit register. If the shiftout signal is set to 1, the contents of the shift register are clocked into a second four-bit register connected to parout.
Design the shift register and test all functionalities. D flip-flop (DFF): A single register (flip-flop) is needed to save the carry-out from the full adder after each clock cycle and present it to the carry-in at the start of the next clock cycle.
Serial Adder Verilog
The register timing should use the rising edge of the clock, and have a synchronous reset (If reset='1' the value of Q is set to '0' at the next rising edge, otherwise Q is set to the value at input D.) You can either create a separate component for the DFF, or simply implement it as a clock-dependent process in the top-level design. Full Adder: You may either use the full adder that you designed in Lab 1, or write a new, simpler version as a single entity and architecture. If you choose the former option, make sure that the vhdl files for all of the components are copied into your new project, so that you can change them (as needed) without affecting the other design Modecontrol: This is a state machine with a single clock input ( clk), that produces three output signals that control the relative timing of the different component ( shiftin, shiftout and reset). Each of these outputs is set high (1) for one clock cycle, and low (0) for the other three. New data are read in by the input shift registers when shiftin is equal to 1. For the next three cycles the contents of the register are shifted out one at a time and sent to the adder. The reset signal is used to prevent the carry-out of the top-most bits in the summation from being carried in to the next calculation.
When reset is set high, the output of the DFF is forced to '0'. The contents of the output shift register are properly aligned once every four clock cycles, just after a four bit summation is completed.
At this time, the shiftout signal is set to 1, and the correctly aligned result is held on serout to be sent to the display. The modecontrol state machine should have four states, with the three outputs correctly defined for each state. Simulate the mode-control block separately to show that it produces a repeating sequence of the three control signals.
When you integrate the final design you may need to adjust the relative timing of the signals to make the adder work properly. Serial Adder: Once you have written and simulated each of the individual components, instantiate them in a top-level architecture resembling the figure above. Simulate, and adjust the timing of the modecontrol component until the adder works correctly. Pay special attention to the carry chain and the alignment of the output. Once the simulation works, implement it in your developer board. Use eight switches for the two four-bit inputs, and four LEDs to display the output. For timing, use the 100 MHz oscillator clock supplied to pin W5 of the FPGA.
If time permits, you can implement the output as numbers using the seven-segment LED display. This can be done by instantiating the VHDL module (.