Cognew in PASM

gambrino · 2008-11-13 17:55

Hello , i read the Propeller programming tutorial and i played the exercises , and i feel that something i didn't understood it good.
1)Can one cog toggle 2 pins simultaneously ? or i should use the parallel processing?
2)How can i toggle 2 pins simultaneously in PASM ? using cognew ? can i write like this to toggle pin16 and 17 simultaneously ? :

{{ AssemblyToggle.spin }}
CON
_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000
PUB Main
cognew(@Toggle, 0) 
DAT

        ORG 0 

Toggle  mov dira, Pin 
        mov Time, cnt 
        add Time, #9 
:loop   waitcnt Time, Delay 
        xor outa, Pin 
        jmp #:loop 

Toggle1 mov dira, Pin1 
        mov Time, cnt 
        add Time, #9 
:loop   waitcnt Time, Delay 
        xor outa, Pin1 
        jmp #:loop 
        
Pin long |< 16 
Pin1 long |< 17 
Delay long 80_000 
Time res 1

Thank you for your help

Harley · 2008-11-13 18:19

I too have that need, gambrino. Here was my approach; probably got the clue from off this forum:

Using a 'temp' register, I've used this

   xor   temp, OUTA  ' combine with pin states
   xor   OUTA, temp  ' then set/clear for desired output

Possibly there are better or faster schemes. I'd welcome any myself.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Harley Shanko

Ariba · 2008-11-14 00:38

To toggle P16 + P17 simultaneously:

{{ AssemblyToggle.spin }}
CON
_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000
PUB Main
cognew(@Toggle, 0) 
DAT

        ORG 0 

Toggle  mov dira, Pins 
        mov Time, cnt 
        add Time, #9 
:loop   waitcnt Time, Delay 
        xor outa, Pins 
        jmp #:loop 

Pins long 1<<16 | 1<<17   'PinMask (set all Pins to 1 which should toggle)
Delay long 80_000 
Time res 1

XOR toggles all Pins which have the Bit set in the Pin Mask. You can toggle 1 to 32 Pins with one XOR.
1<<16 (or |<16) is a more readable form of writing %00000000000000010000000000000000 but in this binary
form, you can see how every bit0..31 of the mask corresponds to a pin PA0..PA31 on the Port.

In PASM all bithandling is done with Bitmasks. Use
XOR to toggle the bits (pins)
OR to set the bits (pins)
ANDN to clear the bits (pins)
MUXxx to set the bits according the C or Z flag value.

Andy

Cognew in PASM

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