PIC16F877A with a 20MHz oscillator

[josh1245]

Helloo!

Can you please tell me how long does a PIC16F877A micro controller take to execute one line of coding when used with a 20 MHz oscillator??

 

[Tahmid]

fosc = 20MHz
tosc = 1/fosc
tcy = 4 * tosc = 4/fosc

So, tcy = [4/(20 * \[{ 10}^{ 6}\])] s = [4/(20 * \[{ 10}^{ 6}\])] * \[{10 }^{6 }\] µs = 0.2µs = 200ns

Hope this helps.
Tahmid.

 

[betwixt]

Note: Tahmid's figures are for one machine instruction (a single non-branching assember instruction).

One line of code may be considerably longer if it is written in a high level language.

Brian.

 

[Tahmid]

Yea, the time calculated is that for one instruction cycle.

In assembly, there are a few 2 instruction-cycle instructions.

In high-level language, one line could be 1 instruction cycle or very long, depending on the line of code.

 

[josh1245]

thank you soo much Tahmid, & Brain... since Im new to micro controllers, I am using MicroC, but not assembly.., can you please tell me how it works with microC if you do not mind.??

 

[Tahmid]

It depends on the instruction / line of code. You can use the stopwatch option in the debugger to check the time.

 

[Ishah]

It depends on the instruction / line of code. You can use the stopwatch option in the debugger to check the time.

Hi Tahmid,

Can you guide me to fill this stop watch of MicroC.

 

[FvM]

Stopwatch runs between breakpoints or single steps in debugging. Nothing to fill out.

 

[Ishah]

Stopwatch runs between breakpoints or single steps in debugging. Nothing to fill out.

Sorry Im new of this, it's quiet shame for me to ask but, it that mean I need to click F9 (start Debugger) ? Where i can check the time.. ?

Thanks FvM.

 

[FvM]

that mean I need to click F9 (start Debugger) ?

I'm sure you'll also find out which hotkeys are available to access
- breakpoints
- single stepping