Using several cogs

eduardomorais

Could anyone give me a program where one makes use of several cogs. I'd like to better understand the use thereof.
I'm using the card propeller parallax. It is has a eight cogs.

Thanks already.

Cluso99

eduardomorais: Firstly welcome to the prop.
Everywhere you look on the forum there is use of multiple cogs. Firstly, the most basic is to use a cog to send/receive to the pc. Next, you can add a VGA monitor (uses a couple of cogs depending on which VGA driver. TV can use 1 or more cogs. A keyboard will use 1 cog. Interfacing to an SD card will use 2 cogs - one for the low level SPI interface and 1 for the FAT implementation. Remember, our drivers take care of a lot of other things normally done in main code is other micros.
So, our FullDuplexSerial object that does serial does more than just perform a UART function, it actually takes care of everything so all you do is place characters into a buffer and take the received characters out of a buffer.

The of course, there is ZiCog which performs a whole Z80 & CPM emulation.

prof_braino

Hi eduardoramos

if you are refering to the prop demoboard (or other board with VGA connector) and find propforth on google code, an example that might be interesting is LowResVGA.f
The propforth kernel runs a user prompt on cog6, which communicates to the PC serial port via cog7. User input entered in the PC terminal propgram is processed interactively.
Cog3 and cog4 are have user prompts which are displayed on the VGA terminal connected directly to the propboard, and the user input is entered from the keyboard connected directly to the propboard.

The user can interact with the cogs at the same time, type input into one cog which and change stuff on the other cogs.

doggiedoc

eduardomorais - here is a short program I put together as a learning exercise for PASM - it uses all 8 cogs to flash 8 LEDS in an endless loop - it ended up looking pretty cool. My version is based on the Assembly example in the Propeller manual.

connect LEDs through resisters to pins 16-23

{{ AssemblyToggle.spin
toggle leds on pins 8 pins 
using all 8 cogs }}

CON
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000

VAR
  long thePin 

  
PUB Main  (loop)
  {Launch cog to toggle LED endlessly}

  repeat loop from 16 to 22
    thePin :=  loop
    cognew(@Toggle, @thePin) 'Launch new cog
    waitcnt(clkfreq/2 + cnt) ' Pause
  thePin := 23                'set Pin for cog 0
  coginit (0,@Toggle, @thePin)   'launch Toggle in cog 0
  
DAT
        {Toggle Pins on cogs}

              org 0                             'Begin at Cog RAM addr 0
Toggle        rdlong  ScratchMem, par
              shl     Pin, ScratchMem
              mov dira, Pin                     'Set Pin to output                              
              mov ScratchMem, cnt                     'Calculate delay time
              add ScratchMem, #9                      'Set minimum delay here
             
              
Increment    waitcnt ScratchMem, Delay               'Wait
              add Delay, IncValue               'Increment Delay value
              max Delay, MaxDelay wc            'Set Maximum Delay 
              xor outa, Pin                     'Toggle Pin
        if_nc jmp #Decrement                    'jump to Decrement loop
              jmp #Increment                       

Decrement    waitcnt ScratchMem, Delay               'Wait
              sub Delay, IncValue               'Increment Delay value
              min Delay, IncValue wc            'Set minimum Delay 
              xor outa, Pin                     'Toggle Pin
        if_c  jmp #Increment                    'jump to increment loop
              jmp #Decrement

                             
Pin           long      1                       'Pin variable
Delay         long       1_000_000               'Clock cycles to delay
IncValue      long          50_000               'increment value
MaxDelay      long      20_000_000               'maximum delay
ScratchMem          res       1                        'System Counter Workspace