PROGRAMMING THE PERIPHERALS OF 8051 535
14.3 | Timers of 8051
e 8051 has two timer units, namely, T0 and T1. ey are independent of each other
and can operate simultaneously.
e functions that a timer can perform are as follows:
i) It can create a delay or an interval of time—then we call it an ‘interval timer’
ii) It can also do counting of the frequency of external signals—then, it is called an
‘event counter’
e basic diff erence in operation between a timer and a counter is that, for the basic
timing, the former uses the clock frequency of the chip while the latter uses an external
frequency.
14.3.1 | Interval Timer
What does an interval timer do?
e timer is just a hardware for creating a delay. When started, it ‘runs’ and by the ...