It consists of the 1st and the 2nd data store units (DS), the 1st and the 2nd impulse realization units (IR), the low-level add unit (LA), the hi-level add unit (HA), the 1st and the 2nd output level judgment units (OLJ), the 1st and the 2nd calculation result selection units (CRS) and the hi-level preservation add unit (HPA). The system clock and the reset signal connect to the 1st and the 2nd DS and the 1st and the 2nd IR respectively. The output enable signal connects to the 1st CRS and the 1st OLJ. The frequency parameter connects to LA, HA and HPA. The multiplying power parameter connects to the 1st OLJ and HA. The occupied-empty ratio parameter connects to the 2nd OLJ. The output of the 1st IR connects to the 2nd OLJ. The output of the 2nd IR is the impulse output of this means. This impulse possesses a hi-precision, changeable frequency and changeable duty ratio.