-Binary Up/down counter with saturation has no output

About Quartus's template--Binary Up/down counter with saturation.

Why it has no output when count_up=0(down count)?My device is EP2C5AT144A7.

Up counter work‘s ok.

// Quartus II Verilog Template

// Binary up/down counter with saturation

module binary_up_down_counter_with_saturation

# (parameter WIDTH=32)

(

input clk, enable, count_up, reset,

output reg [WIDTH-1:0] count

);

reg [WIDTH-1:0] direction;

reg [WIDTH-1:0] limit;

// Reset if needed, increment or decrement if counter is not saturated

always @ (posedge clk or posedge reset)

begin

if (reset)

count <= 0;

else if (enable == 1'b1)

begin

if (count_up)

begin

direction <= 1;

limit <= {WIDTH{1'b1}}; // max value is all 1's

end

else

begin

direction <= -1;

limit <= {WIDTH{1'b0}};

end

if (count != limit)

count <= count + direction;

end

end

endmodule