Using Multiple Cogs in PASM

tholberton · 2012-05-24 01:49

I want to start using multiple cogs in assembly, but i'm not quite sure how to go about that. I've seen a lot of things about using stacks but I'm not really sure what those are used for. Here's what's not working:
CON
_clkmode = xtal1
_xinfreq = 5_000_000

PUB Main
cognew(@test_code, 0)
cognew(@test_code_two,1)

DAT
org 0
test_code
{stuff here}
fit

org 0
test_code_two
{stuff here}
fit

kuroneko · 2012-05-24 01:57

tholberton wrote: »

Here's what's not working:

I am assuming that {stuff here} is some useful/valid code. How do you know it's not working? That said, the cognew part is perfectly valid (with the exception that the second parameter has to be a 4n value).

tholberton · 2012-05-24 02:04

well i just removed the code, and did a simple debug with leds... it's working now. but what you do mean 4n value?

kuroneko · 2012-05-24 02:07

4n: multiple of four

The second parameter to cognew will end up in the par(ameter) register ($1F0). The way coginit/cognew works means that only 14 bits of this parameter can be transferred to the cog. In order to cover the 16bit address range only bits 15..2 are used. Anything else will be cut off (your 1 for the second cog will appear as 0).

tholberton · 2012-05-24 02:07

I take that back... it's not working.
here's the code:

CON
_clkmode = xtal1
_xinfreq = 5_000_000

PUB Main
cognew(@test_code, 0)
cognew(@test_code, 1)

DAT
org 0
test_code
mov dira,#256 {pin 8}
mov outa,#256
fit
org 0
test_code_two
add dira,pin9
add outa,pin9
pin9 long 512 {pin 9}
fit

tholberton · 2012-05-24 02:10

oh, I thought that was the cog id... then what does the parameter do? or what's it used for?

kuroneko · 2012-05-24 02:13

When you post code it helps (us) when you embed it in [noparse]

[/noparse] tags.

As for the code, excution doesn't stop unless you tell it to. IOW after setting the relevant pin to high the cog keeps executing whatever is in memory which may have unwanted side effects (remember that a cog memory is always loaded full size regardless of actual program size). To stop execution simply add a loop or other wait command, e.g.

jmp     #$     ' # optional

waitpeq $, #0

Heater. · 2012-05-24 02:18

So what do you expect it to do and what does it actually do?
I note you are not using test_code_two.
Also be aware that cognew loads 512 longs into your cog no matter how long you think your program is.
So when you cognew test_code_one it also loads the following test_code_two longs. Of course the first cog then runs both codes and then runs whatever junk follows in memory.
Probably not what you want.
Put a jmp to self at the end of your test codes or have each jmp back to their start locations at the end.

kuroneko · 2012-05-24 02:18

tholberton wrote: »

oh, I thought that was the cog id... then what does the parameter do? or what's it used for?

Whatever you want it to do (provided 14bit are enough). People around here usually use it to communicate between different cogs and/or languages.

tholberton · 2012-05-24 02:26

okay, i added the waitpeq, but it's still not turning on pin 9. and i'm still unclear about the parameter part. i'm reading the manual right now

CON
  _clkmode = xtal1 
  _xinfreq = 5_000_000  
PUB Main
  coginit(0,@test_code,0)
  coginit(1,@test_code_two,0)
DAT
org 0
test_code
add dira,#256        {pin 8}
xor outa,#256
waitpeq $,#0
fit


org 0
test_code_two
add dira,pin9
add outa,pin9
waitpeq $,#0
pin9 long 512            {pin 9}


fit

tholberton · 2012-05-24 02:28

oh okay, thanks Heater. and kuroneko that makes sense

kuroneko · 2012-05-24 02:28

tholberton wrote: »

okay, i added the waitpeq, but it's still not turning on pin 9.

May I suggest you stick with cognew for now? By re-starting cog 0 you basically kill the SPIN interpreter (after re/boot usually cog 0 is used) and therefore your second cog is never started. Using cognew will attempt to start the next available cog (e.g. 1 and 2).

tholberton · 2012-05-24 02:31

kuroneko wrote: »

May I suggest you stick with cognew for now? By re-starting cog 0 you basically kill the SPIN interpreter (after re/boot cog 0 is used) and therefore your second cog is never started.

okay, that pretty much made it work. it's written like this now:

CON
  _clkmode = xtal1 
  _xinfreq = 5_000_000  
PUB Main
  cognew(@test_code,0)
  cognew(@test_code_two,0)
DAT
org 0
test_code
add dira,#256        {pin 8}
xor outa,#256
waitpeq $,#0
fit


org 0
test_code_two
add dira,pin9
add outa,pin9
waitpeq $,#0
pin9 long 512            {pin 9}


fit

Pliers · 2012-05-26 05:10

I hope this is not considered hijacking a thread, but I am having the same problem. Two cogs running.
Here is my code and I can not get the intended results. All eight LEDs should be on.

pub main
cognew(@IOtest1,0)
cognew(@IOtest2,0)                        
dat
               org 0
 IOtest1     mov dira, pin        
 loop1           
             mov outa,out1
             jmp #loop1
               
 IOtest2     mov dira, pin        
 loop2           
            mov outa,out2
            jmp #loop2
           
 pin  long  000000_11111111_00000000_00000000 
 out1 long  000000_11000011_00000000_00000000 
 out2 long  000000_00111100_00000000_00000000 
FIT

kuroneko · 2012-05-26 05:26

In short, each cog image should start with an org 0 and should have its own set of variables.

pub main
cognew(@IOtest1,0)
cognew(@IOtest2,0)                        

DAT             org     0

IOtest1         mov     dira, :pin
:loop1           
                mov     outa, :out1
                jmp     #:loop1

:pin            long    %00000000_11111111_00000000_00000000
:out1           long    %00000000_11000011_00000000_00000000

                fit

DAT             org     0               

IOtest2         mov     dira, :pin
:loop2           
                mov     outa, :out2
                jmp     #:loop2
           
:pin            long    %00000000_11111111_00000000_00000000
:out2           long    %00000000_00111100_00000000_00000000

                fit

In your example IOtest2 is assembled for cog location 3 but loaded at 0 which more often than not goes wrong.

turbosupra · 2012-05-26 07:20

Why not make each cog an object? So you can reuse the code in other projects?

Pliers · 2012-05-26 11:18

Thanks kuroneko for the solution.
I very much appreciate your help.

Turbosupra, I have been away from the prop for a while and I'm re-learning the program.
I agree that objects are a great way to build a program.

Thanks again for your help.
Best regards.

Using Multiple Cogs in PASM

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