A student uses the code below in a continuous loop to generate a 200 Hz square wave, noting the period of 200 Hz is 5 ms. redled = 1; // flash red led wait_ms(2.5); redled = 0; wait_ms(2.5); He is...

A student uses the code below in a continuous loop to generate a 200 Hz square wave,

noting the period of 200 Hz is 5 ms.

redled = 1; // flash red led

wait_ms(2.5);

redled = 0;

wait_ms(2.5);

He is then surprised to measure a frequency of 250 Hz. Explain why this is so.