Some basic questions regarding T States

[vsmguy]

I am using CCS PCH 4.084, PIC18F2550.

With this at mind :

1. Is a 32Mhz INTRC possible on a PIC18F2550?

Tried doing it and everything started to run almost 4 times as slow compared to when I ran it @8MHz

I can only visually watch the delays of ~1 sec that blinked LEDs.
With an 8MHz INTRC, the timings seem to bo correct though.

I was careful in :

i. setting the #use delay(clock=8000000) and #use delay(clock=32000000) as applicable.
ii. setting the setup_oscillator(OSC_8MHZ | OSC_INTRC); and setup_oscillator(OSC_32MHZ | OSC_INTRC); respectively

2. Is there any easy/quick way of knowing how many T states a C function (say the CCS Standard library function) takes?

I mean - not looking at the code (I believe that CCS Standard library functions may not figure in the ASM list at all maybe?)

3. Are there any PIC18F instructions that can take variable number of T States for the same operands?

4. Regarding Timer0, does it seem to be the case that either CCS or (maybe!) PIC18F itself does not have "auto reload" of the preload value so that I need not do that explicitly everytime I have a timer overflow?

This would seriously hamper my design as I am sure there would be jitter between the timer overflowing and me setting the overflow value (probability increases as time period decreases!)

Because of this, what I am speaking aloud to myself "PIC does not have automatic timer0 reload?! Even the near obsolete 8051 has this."

"Bonus" questions:

6. Can the index of a CCS array for a PIC18F be:
i. int16
ii. int32

7. I connected a 8E (Ohm) speaker to RB3 to listen to some audible square waves. It looks like after I increase the duty cycle (transferred power) of the output signal to a certain higer value, there is complete silence and NO MORE sound seems to come out.

First time I believed that I had burnt the pin, but I can reproduce this any time! Is there some "protective feature" in the PIC that turns off a pin/port/PIC if too much current/power is drawn from a pin/port?

That would be all (or should I have created a separate thread for each post instead?)

[PCM programmer]

Most of this can be answered by looking at the PIC data sheet.
There's a block diagram of the oscillator in the data sheet:

[vsmguy]

Thanks for the quick reply, and congrats on the milestone of 10k+ posts!

I would like some answers to the other questions though, specially 4 onwards!

[PCM programmer]

What about reading the data sheet ?

Read the section on Timer 2:

[ckielstra]

Question 6) Yes, int16 and int32 can be used as an index, I think. You can check this yourself with a tiny test program and studying the generated assembly output from the *.lst file.
Int32 does not make a lot of sense because of the limited memory capacity. An int16 will address 64k bytes. The PIC18 has maximum 4k RAM.
The PIC processor is not efficient in index based addressing, it creates a lot of overhead, so use with care.

7) Complete silence == PIC death.
Again, read the datasheet and do the maths.

[vsmguy]