GOTO absolut address - is that possible?

[keymuu]

Hi!

I have been looking around for some info how to jump to an absolute address (not label) but without success. So, I have not found that info...

I have a need to jump to the absolute address 0F4C.

Knowing that the banks are one byte wide and for example a bra instruction needs to calculate the address to the final location, jumping over the bank borders.

How do one calculate a long jump address?
Or how can on do that with the assembler?

If you know how to do it, please advice...:)

[Darrel Taylor]

@ GOTO 0x0F4C

[Ioannis]

Isn't necessary to change pages? As this is in assembly, PBP does not take care of this, I suppose.

Ioannis

[Darrel Taylor]

From another thread I saw he's using an 18F4550 with a USB bootloader.

So nope. No Pages to worry about.
<br>

[Acetronics2]

Hi, Darrel

While on that subject ...

I use, on a 16F88 :




' If program lost

@ ORG 4094 ' Pointer to the end of program
@ CLRF PCLATH ' pointer in the right page ( lol )
@ GOTO INIT ' It's gone for another round...
'
@ END



Works and compiles fine ... BUT

No way to use Breakpoints in MPSIM when lines not commented ...

Do you have any idea about that ??? ( µChip tells ... go and see Melabs !!! - as always ... )

Alain

[keymuu]

@ GOTO 0x0F4C

Thank you Darrel! :)

As not being so familiar with the assembler I did not see/realize that there is also GOTO and not just BRA. Now I know that BRA is for short jumps only and GOTO can jump anywhere.

Can you find a "good" 4550 tutorial (not datasheet) somewhere on the web?

Tanks again...

[Darrel Taylor]

Don't know of any 4550 tutorials.

The PIC18C Reference Manual has a little more info regarding the instruction set. But not enough more to be of much help.
http://ww1.microchip.com/downloads/en/DeviceDoc/39500a.pdf

Really, the datasheet has the best info available.
Once you get used to reading them, it gets easier.

Alain,

I haven't used mpsim for awhile, and there's been a few MPLAB upgrades in the mean time. I was going to try your problem, but now PBP isn't even an option in my MPLAB anymore.

I'll have to reinstall the dll again. Been too long, I forget how. :eek:
<br>

[Archangel]

Hi, Darrel

While on that subject ...

I use, on a 16F88 :




' If program lost

@ ORG 4094 ' Pointer to the end of program
@ CLRF PCLATH ' pointer in the right page ( lol )
@ GOTO INIT ' It's gone for another round...
'
@ END



Works and compiles fine ... BUT

No way to use Breakpoints in MPSIM when lines not commented ...

Do you have any idea about that ??? ( µChip tells ... go and see Melabs !!! - as always ... )

Alain
Hi Alain, Just curious . . . ASM comment is ; not ' yes?

[Darrel Taylor]

Hi Alain, Just curious . . . ASM comment is ; not ' yes?
Way to go Joe!
I didn't even see that.

Can't imagine how it compiled.
<br>

[Archangel]

Thanks Darrel :) 30 years of snivel service teaches you to pick fly specks out of the pepper ELSE Nazi bosses frag your reputation.

[Acetronics2]

Hi Alain, Just curious . . . ASM comment is ; not ' yes?

Hi, joe

YES ... looks right, but compiles and runs fine.

After all, It's a PBP program ... intelligent compiler ? lol : might be.

In fact, MPLAB accept both " ; " and " ' " ... as MPLAB Editor is set to "Basic" mode. Why not use what computers offer for ease of work ( Humour ...)

Changing " ' " to " ; " do not change anything ...

You're quite right : Manual says " line is sent verbatim" ... but, obviously, comments are not sent !!!


Alain

[Archangel]

Hi, joe

YES ... looks right, but compiles and runs fine.

After all, It's a PBP program ... intelligent compiler ? lol : might be.

In fact, MPLAB accept both " ; " and " ' " ... as MPLAB Editor is set to "Basic" mode. Why not use what computers offer for ease of work ( Humour ...)

Changing " ' " to " ; " do not change anything ...

You're quite right : Manual says " line is sent verbatim" ... but, obviously, comments are not sent !!!


Alain
Ask questions and learn, Right? <br>PBP & Assembler, like mixing 10 oz alcohol and 10 oz water, you do not get 20 oz of liquid.
I read books AND this forum, sometimes experience and books do not agree. Anyway I try to help and am not embarrassed to learn from the masters.

[Acetronics2]

Hi,

Here is the Melabs answer :




Below is the response that I received from MicroEngineering Labs regarding your issue:

I've found that the problem only occurs when the assembly-language jump to our INIT routine is included:

@ GOTO INIT

I'm guessing that since the INIT label isn't a label in the program source code (it is an internal label PBP creates), it is not something that can be resolved for source-level debugging.

User code should not jump to our INIT routine. If he wants to restart his program, he should declare a label in the source and use it instead.

Charles Leo
microEngineering Labs, Inc.



... now just have to find WHERE to place this "dummy" label ...

ring you asap.

Alain

[Acetronics2]

Ok, it's solved




'Defines

DEFINE OSC 4


'************************************************* ****************************
'************************************************* ****************************
'Config

'Program Configuration Register 1
@ __CONFIG _CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_OFF & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_ON & _PWRTE_ON & _WDT_ON & _XT_OSC

'Program Configuration Register 2
@ __CONFIG _CONFIG2, _IESO_OFF & _FCMEN_OFF


'************************************************* ****************************
Restart:

INTCON = %01000000 ' RB0 interrupt
OPTION_REG = %11000111 ' TMR0 pour sous régime PS = 256 ( Rpm = 460 )
T1CON = %01010000 ' %01000000
CCP1CON = %00000101
PIE1 = %00000100

CMCON = 7
CVRCON = 0

ANSEL = 0
ADCON0 = 0

....

'************************************************* ****************************
'************************************************* ****************************
' If Program counter lost

@ ORG 4094 ' Goto the very last lines ( µP is a 16F88 )
@ CLRF PCLATH ' right page for 12/16F( lol )
@ GOTO _Restart ' Go on again !!! ...
'
@ END



Look at the "Restart" Label ... it must be placed before the very first PBP command : here, an " INTCON = " statement.

The ASM " Init " ( no underscore !!! ) label is automatically placed here by PBP in the .asm generated.

This way, all the registers are re-set to the convenient values ...