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Why 8085 works at the half frequency of the crystal oscillator?
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Why you use crystal oscillator in 8085 microprocessor?
The oscillator provides the basic clock of a microcontroller to be able to execute the instructions in a stable, periodic way. It is often used for other peripherals too, like timer, UART, etc. as frequency base, usually divided by a clock divider for integer factors, or by PLL for rational factors. If the timing accuracy of these functions is not important, a simple RC oscillator can be used. Many microcontrollers have it internally. Accuracy is in 1...10% range. For better accuracy and temperature stability, a resonator can be used. For applications where timing is critical, a crystal can be used. Most micros have built-in oscillator, so only a crystal and two caps are needed. For those which have no built-in oscillator, external crystal oscillator module may be used. There are OCXO and TCXO modules available for very high stability needs.
Why jump instruction is invariably written in the vectored location of an interrupt request?
An interrupt makes the processor to jump to a vectored location in memory where the ISR is written. By observing the vectored locations for various interrupt inputs of 8085, we know that there are only 4 or 8 bytes allocated for ISR. This memory space is not sufficient for writing any code to process an interrupt. So we write a jump instruction that makes the processor jump to a location in user memory and write the ISR starting from that location.Example: suppose there is an interrupt signal to 8085 at RST 6.5. The call location for RST 6.5 is 0034H. The address space available is 4 bytes. So if we write instruction jmp 2300H at 0034H, then we can write ISR in memory locations starting from 2300H.
Why you connect 6.28MHz crystal oscillator in 8085microprocessor instead of 3.14MHz crystal oscillator?
Internally two crystal oscillator cycles are used as one single cycle. During one single crystal cycle it is made to logic high and logic low in next cycle so, that 50% duty cycle is maintained.
Give the clock out frequency and state time T of 8085 when the crystal frequencies is 5MHz?
The clock out frequency of an 8085 is one half the crystal frequency. The period of one T cycle is the inverse of the clock frequency. At a crystal frequency of 5MHz, the clock is 2.5MHz, and T is 400 ns.
Why microprocessor frequency is half of crystal frequency?
The crystal oscillator frequency in the Intel 8085 is divided by 2 because Intel designed it that way. Internal actions in the 8085 occur at various points in the cycle and, by dividing by 2, Intel could create 4 distinct points in the cycle where various edges could perform actions.
Specify the crystal frequency required for an 8085 system to operate at 1.1mhz?
The crystal frquency in an 8085 system is twice the desired clock frequency, so a crystal of 2.2 MHz is required to operate at 1.1 MHz.Note: Clock frequency is not the same as instructions per second, because the instructions in an 8085 take a variable number of clock cycles, between 4 and 18, to execute.
What is the crystal frequency required for an 8085 system to operate at 101 MHz?
There is no 8085 that operates at 101 MHz. The fastest 8085 operates at 12 MHz, requiring a 24 MHz crystal.
Why you use crystal oscillator in 8085 microprocessor?
The oscillator provides the basic clock of a microcontroller to be able to execute the instructions in a stable, periodic way. It is often used for other peripherals too, like timer, UART, etc. as frequency base, usually divided by a clock divider for integer factors, or by PLL for rational factors. If the timing accuracy of these functions is not important, a simple RC oscillator can be used. Many microcontrollers have it internally. Accuracy is in 1...10% range. For better accuracy and temperature stability, a resonator can be used. For applications where timing is critical, a crystal can be used. Most micros have built-in oscillator, so only a crystal and two caps are needed. For those which have no built-in oscillator, external crystal oscillator module may be used. There are OCXO and TCXO modules available for very high stability needs.
What will happen if crystal frequency of 8085 is increased from 5 to 20 MHz?
Since the 8085 has a maximum clock frequency of 6 MHz, increasing the crystal frequency from 5 MHz to 20 MHz, a corresponding clock frequency change of 2.5 MHz to 10 MHz, the chip would malfunction.
How can you determine the duration of one T-state?
The duration of one T-state is one divided by the clock frequency, or two divided by the crystal frequency. This is for the 8085.
If the frequency of the crystal connected to 8085 is 6MHz calculate the time to fetch and executed NOP instruction?
At a crystal frequency of 6MHz, the 8085 microprocessor has a clock frequency of 3MHz, or a period of 333 nanoseconds. The NOP instruction requires four clock cycles, three to fetch and one to execute, so the NOP instruction with a crystal frequency of 6MHz would take 1.333 microseconds to fetch and execute. This does not include wait states, each of which would add 0.333 microseconds to the timing.
What is crystal in microprocessor 8085?
crystal is a oscilltor in microprocessor
What is the clock speed of 8085 mp?
The clock speed of the 8085 depends on the particular chip chosen. The basic 8085 could run up to around 3 MHz. The -1 version could run up to around 6 MHz. The -2 version could run up to around 5 MHz. In each case, the crystal frequency had to be exactly twice the desired clock frequency, i.e. 6 Mhz, 12 MHz, and 10 MHz, respectively. In all cases, the minimum clock frequency was 500 KHz. (Crystal 1 MHz)
What is operating frequency of microprocessor?
The operating frequency of 8085 is 3 mhz to 5 mhz
