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QUESTION 3 [151 3.1 If the frequency of a crystal connected to an MCS8051 is 25 MHz, what will be the starting point which needs be loaded into TLO and THO that will give a delay of 30ms before the timer rolls over? Assume 16-bit mode is used. (3) 3.2 Use C language and generate a 1 Hz pulse on P3.5 using Timer I and timer interrupts of the MCS8051 micro controller. The HIGH and LOW time must thus be 500ms. Assume the crystal used is 12MHz. You must also set up Timer 0 as a counter and determine the frequency of an unknown pulse which is applied to pin P3.4 (TO). You can assume that the frequency is below 100 Hz. Use the HIGH period of P3.5 to open the counter for counting the pulses. Only half of the pulses will be counted as the timeframe is 500ms, which implies that the counted pulses must be doubled to get the real frequency. During the LOW stage of P3.5 the frequency must be displayed in BCD format on Pl, meaning it can be viewed on seven segment displays. The measured frequency will thus be updated every time the pulse on P3.5 goes low. Use both the timer and counter in 16-bit mode. (12)