Basic example of lpm_counter1 disabled when in overflow

carry_out (the overflow) never goes high because you're clearing the counter before it ever has a chance to, at least in the simulation waveform you show here. Since you're using it as the clock for the dff (a big no-no since you're creating a gated clock; put it on clock enable for the dff instead), the output of the dff is dictated only by the A_clear signal.