what that mean shift left and shift right in this picture?

  

  

Is it need shift left and shift right?

I need check my solution. if any error in my solution, edit and teach me why. Specially, its hard to finish (c)

And If any good video that teach about it, tell me link.

            

  

Multifunction Registers with Separate Control Inputs Id 0 0 0 OOO OLL 0 1 0 1 1 0 PPPHOOOO shr shl Operation 0 0 Maintain present value 1 0 1 1 0 1 1 0 1 1 1 0 OO, 1 Truth table for combinational circuit Inputs Id shr shl 0 0 0 1 1 1 OOHH OOHA 0 1 0 1 0 1 1 0 0 1 1 OHOHOHOH 0 1 0 0 1 Shift left Shift right Shift right-shr has priority over shl Parallel load 0 Parallel load - Id has priority Parallel load - Id has priority Parallel load - Id has priority Outputs s1 SO 0 0 1 1 OLLLOOOO 1 0 1 0 1 0 1 1 1 0 0 0 Note Operation Maintain value Shift left Shift right Shift right Parallel load Parallel load Parallel load Parallel load shr in Id shr shl Figure 19 combi- national circuit s1 s0 00 1 0 shr_in s1 s0 0 1 1 1 Operation Maintain present value Parallel load Shift right Shift left 13 12 11 10 11 13 12 11 10/ shl_in Q3 Q2 Q1 QO Q3 Q2 Q1 Q0 8 shl_in s1 = ld'*shr'*shl + ld'*shr*shl' + Id'*shr*shl s0 = ld'*shr'*shl + Id l'xshmishl+l)? a