Minimum in array

Solution 1:

When you unroll the for loop, this is what it would look like:

always_ff @(posedge clk, posedge rstN) begin
    if(rstN == 1'b1) begin
        currRes <= 4'b1111;
    end
    else begin
        if( resArray[0] < currRes) begin
            currRes <= resArray[0];
            minVal  <= resArray[0];
        end
        if( resArray[1] < currRes) begin
            currRes <= resArray[1];
            minVal  <= resArray[1];
        end
        if( resArray[2] < currRes) begin
            currRes <= resArray[2];
            minVal  <= resArray[2];
        end
    end
end

You end up with multiple nonblocking assignments to the same register (currRes).

On the 1st posedge of the clock after reset, all 3 if clauses are true, and the last assignment wins:

            currRes <= resArray[2];

So, currRes is assigned the value 3, not 1.

The same is true of minVal.

You need to sort the 3 input values, then compare the minimum of those values to the current minimum.