Anonymous
Anonymous asked in Science & MathematicsEngineering · 1 decade ago

Why in 8085 microprocessor, the clock frequency is divided by two?

Originally the clock frequency is 6.144 MHz, but internally it takes only 3.072 MHz. WHY???

3 Answers

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  • 1 decade ago
    Favorite Answer

    you are freering to the internal clock speed and the external clock speed corect? ECLK or ECLKNOT are external clocks to the microprocessor. they do not run it. they are for the microprocessors supporting hardware. the internal frequency is what the processor actually uses. the ECLK is divided by two( a 6MHZ cycle take half as long a 3MHZ, right). the reason external (E) clocks run twice as fas as a processor is because there is not much data that can be processed in one cycle. it also allows the supporting architecture to access the data twice as it is processed. think about accessing a memory slot, it would use one ECLK cycle to locate the slot and one ECLK cycle to right the data to the processor. reading memory is a very simple task, but it still take two cycles. if the ECLK didnt run at twice the speed of the internal clock, the processor would be idle half of the time.

    they didnt screw you by lowering the internal frequency. they helped you by doubling the speed of the supporting hardware.

  • Nomadd
    Lv 7
    1 decade ago

    Internally it operates at 6.144. It's bus speed is knocked down to 3.072 because the memory and chipsets could only go that fast, and the CPU couldn't have taken data at full speed anyhow.

  • 1 decade ago

    I dont know exactly, but the First answer seems convincing...

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