Write a program using Timero to generate a square wave with a frequency of 2 kHz and 4 kHz on PORTB RB1 and PORTB RB5 respectively. PORTB RB7 will be used as a switch to select the frequencies. If RB7 = 0 (Low), the 2 kHz square wave will be generated and if RB7 = 1 (High), a 4 kHz square wave will be generated. Examine the frequencies using the MPLAB Logic Analyzer and Stopwatch. Modify the count value to make sure that the frequencies are as close as possible to 2 kHz and 4 kHz. (Assume XTAL = 20 MHz)