different style of coding to reduce logic resources??

Thank You.

I still do not see the difference between the two coding styles. In the example below, which is a stripped down example from case 1 and case 2 with the variables renamed, what extra logic is needed for r2 that is not needed for r1, It is my understanding that all RHS operations are combinatorial.

wire a;

wire b;

wire c;

reg [1:0] r1;

reg [1:0] r2;

assign c = { a, b };

always @(negedge clk or negedge rst_n)

begin

if ( rst_n == 0 )

begin

r1 <= 0;

r2 <= 0;

end

else

begin

r1 <= c;

r2 <= { a, b };

end

end