How to configure a clock rate of 50 Hz with a prescaler with TI Microcontrollers?
You'd just use an integerin a timer interrupt, and increase it (count) as many times as necessary to reach 50 Hz.

In your case, your timer interrupt would count up to 62500 / 50 = 1250, then reset to zero, and also trigger the update. 

pseudo-code:

global integer counter; //initialize to 0

void timer_interrupt_service_routine():
  counter = counter + 1
  if counter larger or equal 1025:
     counter = 0
     update_the_display()


It's as easy as that. Counting is cheap.