Question

1. Consider a timer that is clocked at 200 MHz.

1. What value should be loaded into the timer to set the timer for 10 ms? [25 points]
2. How much time will elapse if the timer is loaded with 0x0210? [25 points]

Answer 1

How much time will elapse if the timer is loaded with 0x0210?

Answer:-

Given, Timer clock frequency = 200 MHz, Count = 0x0210 hex = 528 decimal

Time for one clock cycle = 1/200Mhz = 5 x 10^-9 sec = 5 nano sec

Time elapsed = ( 65536 - 528) x ( 5 x 10^-9 ) = .325 ms

The time elapsed is .325 x 10^-3 sec

What value should be loaded into the timer to set the timer for 10 ms?

Answer:-

Given, Timer clock frequency = 200 MHz

Time for one clock cycle = 1/200Mhz = 5 x 10^-9 sec = 5 nano sec

10 ms = ( 65536 - count) x ( 5 x 10^-9 )

But, the maximum delay that can be provided by this timer is .327680 ms.

For obtaining the timer value of 10 ms, the timer need to run 10/.327680 times , that is 30 times.

Therefore, we need to load the timer with maximum value 0xFFFF and the timer should run with this value reloaded 30 times to obtain the delay of 10 ms.