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-One of the most common and least expensive crystals available is the 3.58 MHz crystal used in color television sets. What hex value would have to be loaded into the counter in Figure 9- 12 in order to use the 3.58 MHz crystal to derive the 60Hz reference signal for the clock?
A) E912
B) 63C0
C) 16ED
D) E3C0

Question

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-One of the most common and least expensive crystals available is the 3.58 MHz crystal used in color television sets. What hex value would have to be loaded into the counter in Figure 9- 12 in order to use the 3.58 MHz crystal to derive the 60Hz reference signal for the clock?
A) E912 
B) 63C0 
C) 16ED 
D) E3C0

Quizplus · Accepted Answer

The counter in Figure 9-12 is a 16-bit counter. The hex value that would have to be loaded into the counter in order to use the 3.58 MHz crystal to derive the 60Hz reference signal for the clock is E912. This is because the counter counts up to 65,535 (FFFF hex) and then resets to 0. The 60Hz reference signal has a period of 16.67 ms, which is equivalent to 10,000 counts of the 3.58 MHz crystal. Therefore, the counter must be loaded with a value that is 10,000 less than 65,535, which is E912 hex.

‪ -One of the Most Common and Least Expensive Crystals Available