The clock divider module is mainly used to generate the specified
clock frequency to trigger the A/D converter and control
the dc servomotor. A 1-MHz quartz oscillator is used here to
supply the clock frequency of the FPGA chip. We use the clock
divider module to reduce 1 MHz to the specified clock frequency.
For example, the CLMR only runs about 500 Hz. It
may result in unstable vibration of the dc servomotor if a high
working clock frequency is utilized. The clock divider module
is composed of an up-counter and a D flip-flop. We exploit the
up-counter to count a double clock frequency, and then we can
get the specified clock frequency after the D flip-flop