Fast Loop in PICBASIC Pro

[mister_e]

could be...

DEFINE OSC 20
TRISB.0 = 0
PORTB = 0
pauseus 0 ' do nothing good but include PAUSEUS?C macro
TRISB.0 = 0
PORTB = 0
start:
asm
    CHK?RP PORTB
    local a=0
    while a<16        
        BSF PORTB,0
        nop
        PAUSEUS?C 12
        BCF PORTB,0
        nop
        PAUSEUS?C 12
a+=1
    endw
endasm
pause 100
goto start

now play with the a < x value, and look what happen to your code size.. interesting eh?

Now compare the code size of

PORTB.0 = 1   
@ nop
Pauseus 12
PORTB.0 = 0     
@ nop
PAUSEUS 12

copy and pasted 16 times, with the one generated with my solution... mmm interesting

Sometime MPASM directive are really handy!

EDIT: you could also use

@   local a=0
@   while a<16
        PORTB.0=1
        @ nop
        PAUSEUS 12
        PORTB.0=0
        @ nop
        PAUSEUS 12
@a+=1
@       endw

If you don't like the PAUSE?C, BSF, BCF option... both generate the same code.

[paul borgmeier]

Steve, I did compare code space

171 for 16X of my block (MPASM)

211 for your code as posted
191 (with the second nop removed from yours - which makes T = 25 uS)

it is interesting.

Now, the question for me is how the ASM while directive checks without adding time???

EDIT (after looking up while) - I see .... it doesn't check .... now I understand your comment about code space and it is a handy directive :-) THANKS

[mister_e]

MIIP, there's something weird... if i use a 16F877 and this....

DEFINE OSC 20
DEFINE LOADER_USED 1
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1
DEFINE HSER_SPBRG 129 ' 9600 Baud @ 0.16%
DEFINE HSER_CLROERR 1 ' Clear overflow automatically


pauseus 0
TRISB.0 = 0
PORTB = 0
start:
asm
    CHK?RP PORTB
    local a=0
    while a<16        
        BSF PORTB,0
        nop
        PAUSEUS?C 12
        BCF PORTB,0
        nop
        PAUSEUS?C 12
a+=1
    endw
endasm

pause 100
goto start

it compile 207 Word

if i use...

DEFINE OSC 20
DEFINE LOADER_USED 1
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1
DEFINE HSER_SPBRG 129 ' 9600 Baud @ 0.16%
DEFINE HSER_CLROERR 1 ' Clear overflow automatically


pauseus 0
TRISB.0 = 0
PORTB = 0
start:
    ' #1
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #2
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #3
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #4
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #5
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #6
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #7
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #8
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #9
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #10
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #11
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #12
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #13
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #14
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #15
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

    ' #16
    PORTB.0 = 1   
    @ nop
    Pauseus 12
    PORTB.0 = 0     
    @ nop
    PAUSEUS 12

pause 100
goto start

Still 207 words...

EDIT: OK DUDE we hit the button at the same time or...so.