Consider an 8-bit shifting circuit that can perform rotating right or rotating left. An additional 1-bit control signal, lr, specifies the desired direction.
Design the circuit using one rotate-right circuit, one rotate-left circuit, and one 2-to-1 multiplexer to select the desired result. Derive the code.
Derive a testbench and use simulation to verify operation of the code.
Synthesize the circuit, program the FPGA, and verify its operation.
This circuit can also be implemented by one rotate-right shifter with pre- and post-reversing circuits. The reversing circuit either passes the original input or reverses the input bitwise. Repeat steps 2 and 3.
Check the report files and compare the number of logic cells and propagation delays of the two designs.