Shiftout question.

[muddy0409]

Hi all, once again a question for the brains trust.
I am using shiftout to drive some shift registers. Everything seems to work OK so far, BUT there is a question:
The manual says SHIFTOUT, Datapin,Clockpin,Mode,[data stuff] and then says the Datapin & Clockpin can be straight numbers, Port pin names, or variables.
So far so good.
I am using
DAT var portd.3 which is common data pin for all shift regs
sect VAR byte, (up the top with the other variable defs.)
SHIFTOUT DAT,sect,5,[S1]
S1 is the data byte,

sect is a variable simply containing a number 0 - 7 which is the portb pin for the clock of the 8 shift registers.

NOWHERE do I define that the number in sect variable is in fact portb.sect or anything like that, SO HOW DOES THE BLOODY THING KNOW THAT'S WHAT I MEAN????? 'COS IT WORKS????

Intriguing, ain't it??

Thanks, as always

[skimask]

Sounds like a holdover from BS2, sorta like where you can use just the plain number (0-7, 8-15) to use as an alias for a pin on PortB or PortC (or PortD, not sure). Automatically defined, handled in the background, etc.etc. Heck, if it works...who cares :)

[Darrel Taylor]

Hi Peter,

Those are "PIN Numbers".
Their location is specified by PORTL and PORTH.

See posts #4, 12 and 14 here ...
http://www.picbasic.co.uk/forum/showthread.php?t=6013
<br>

[Pic_User]

Check this out:)


For compatibility with the BASIC Stamp, pins used in PicBasic Pro Compiler commands may also be referred to by a number, 0 - 15. This number references different physical pins on the PICmicro MCU hardware ports dependent on how many pins the microcontroller has.

If a port does not have 8 pins, such as PORTA, only the pin numbers that exist may be used, i.e. 8 - 12. Using pin numbers 13 - 15 will have no discernable effect.

This pin number, 0 - 15, has nothing to do with the physical pin number of a PICmicro MCU. Depending on the particular PICmicro MCU, pin number 0 could be physical pin 6, 21 or 33, but in each case it maps to PORTB.0 (or GPIO.0 for 8-pin devices, or PORTC.0 for a PIC14000).

-Adam-

[muddy0409]

Hmmmm..
Yeah, I thought it was probably sumpthin' like that. Is there any documentation around for the pin numbering as mentioned and as to what port lines they refer to on different PICs??

[Pic_User]

PicBasic Pro Compiler manual
http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1512&stc=1&d=1175525419
-Adam-