Write a program to drive the LED circuit in Figure 4.16 and display one LED at a time from the one driven by pin 7 toward the one driven by pin 0 and then reverse. Repeat this operation forever. Each LED is lighted for about 400 ms assuming that the HCS12 uses an 8-MHz crystal oscillator to generate a system clock. Use the RTI to trigger the change of the LED light patterns. It may take several RTIs to trigger one change of the LED pattern for this problem.