8051 Microcontroller Interrupt

Interrupt There are five interrupt sources for the 8051, which means that they can recognize 5 different events that can interrupt regular program execution.  there are five interrupts :,TF0,(INTR1)',TF1,RI/TI Each interrupt can be enabled or disabled by setting bits of the IE register. Likewise, the whole interrupt system can be disabled by clearing the EA bit of the same register. . Now, it is necessary to explain a few details referring...

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Timer & Counter control Logics of 8051 Microcontroller

TIMING  If a counter is programmed to be a timer, it will count the internal clock frequency of the 8051 oscillator divided by 12d.  As an example, if the crystal frequency is 6.0 megahertz, then the timer clock will have a frequency of 500 kilohertz. The resultant timer clock is gated to the timer by means of the circuit shown in Figure.  In order for oscillator clock pulses to reach the timer, the C/(T)' bit...

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Timer & Counter of 8051 Microcontroller

Counters and Timers Many microcontroller applications require the counting of external events, such as the frequency of a pulse train, or the generation of precise internal time delays between com­puter actions. Both of these tasks can be accomplished using software techniques, but software loops for counting or timing keep the processor occupied so that other, perhaps more important, functions are not done. To relieve the processor...

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Branch Instruction Of 8051 controller

Branch Instructions There are two kinds of branch instructions: Unconditional jump instructions: upon their execution a jump to a new location from where the program continues execution is executed. Conditional jump instructions: a jump to a new program location is executed only if a specified condition is met. Otherwise, the program normally proceeds with the next instruction. ACALL addr11 - Absolute subroutine call addr11:...

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Data Transfer Instruction of 8051 controller

Data Transfer Instruction of 8051 This instructions are used to copy the content of source operand to Destination operand MOV A,Rn - Moves the Rn register to the accumulator The instruction moves the Rn register to the accumulator. The Rn register is not affected. EXAMPLE:   Before execution: R3=58h After execution: R3=58h A=58h MOV A,@Ri - Moves the indirect RAM to the accumulator Description: Instruction moves the indirectly...

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