Assignment 23 (Assigned October 27)

1. Using D flip-flops and multiplexers, design a 4-bit general-purpose shift register. The 4-bit shift register block has shift-in and shift-out bits at both left and right ends as shown in the figure below. The type of shift is controlled by a 2-bit shift code as specified below.

Shift Code (Sh/Ld Lf/Rt)	Shift type
1 0	Shift Left
1 1	Shift Right
0 0	Do not change
0 1	Load a new value

 



 

2. Using the 4-bit shift register block as designed in Problem 1 and multiplexers, design a 8-bit shift data block. The most significant four bits for this block are input on a 4-bit data bus and the least significant four bits are stored in a 4-bit shift register block. The type of shift is controlled by a 2-bit shift code as specified below.