Question

HSC12 Microcontroller

To create a delay using the Output Compare Channel 6, we add a number of cycles (CCOUNT)to TC6 and then wait until TCNT is equal to TC6. This happens when TLFG1(6) =1. Assuming an E-clock of 24 MHz: Complete the following table in order to generate the given delays:

CCOUNT	Prescaler	Delay
		1 us
		100 us
		500 us
		2 ms
		80 ms
		300ms

Answer 1

Timer advances after each clock cycle and it is 16-bit timer which means it can only count up to 65536

For getting delays grater than 65536*t_clk ,we can use prescaler

Delay can be calculted as follows

Lets find out,what delay can max count genrate with prescalar as '1'

So upto 2.730 milli Seconds prescalar of '1' is enough

For prescaler 2,4,8,16,32,64,128 and full count delays will be

Prescalar should be chosen such that required delay should be just less that max count delay,only tthen delay will be more accurate.

For 80msec prescaler 32 should be chosen

For 300msec prescaler 128 should be chosen

Delay	Prescalar	CCount
1us	1	24
100us	1	2400
500us	1	12000
2ms	1	48000
80ms	32	60000
300ms	128	56250