MICROPROCESSOR AND MICROCONTROLLER

Detailed explanation-1: -Which of the timer can operate in the 16 bit condition? Explanation: Timer0 and Timer2 can operate in the 8 bit condition while only Timer 1 operates in the 16 bit condition.

Detailed explanation-2: -Timer mode “1” is a 16-bit timer and is a commonly used mode. It functions in the same way as 13-bit mode except that all 16 bits are used. TLx is incremented starting from 0 to a maximum 255. Once the value 255 is reached, TLx resets to 0 and then THx is incremented by 1.

Detailed explanation-3: -Timer 0 can be operated both as a timer and counter. All the parts to the left are the clock source circuits. T0CON (Timer 0 Control) register is used to program the timer and includes the bits shown in figure (T0CS, PSA etc.) The clock source can be internal or external and is controlled by T0CS bit.

Detailed explanation-4: -Mode 0 of Timer/Counter The Mode 0 operation is the 8-bit timer or counter with a 5-bit pre-scaler. So it is a 13-bit timer/counter. It uses 5 bits of TL0 or TL1 and all of the 8-bits of TH0 or TH1.

Detailed explanation-5: -Since the timer T0 is virtually 16-bit register, the largest value it can store is 65535. In case of exceeding this value, the timer will be automatically cleared and counting starts from 0. This condition is called an overflow. Two registers TMOD and TCON are closely connected to this timer and control its operation.