My third Attempt At ASM

SailerMan

Last night I wrote a Spin program to Decode and Send Sony IR Signals.. I got it all working and decided to see if I could write it in PASM.

I'm a novice in ASM period but with a lot of reading and more reading my first program was a simple binary counter to LED's

My second program sent data to a 74hc595 Serial to Parallel Latch.

My Third Program decodes a sony remote and displays Key Value and Device. I was hoping that someone with more experience than me can read over this program and show me some code optimization techniques.
Currently this program works!!

Thanks in Advance for any help,
Eric

Con
        _clkmode        = xtal1 + pll16x
        _xinfreq        = 5_000_000
         
    
        
Var
      Long      P
      Long      O  
      
Obj
  Debug         : "TV_Text"

  
Pub Main|Temp,Index
  P:=16
  Debug.start(12)
  CogNew (@Entry,@P) 
 
Repeat 
   
   Debug.Out(1) 
   Debug.Bin(O,20)
   Debug.Out(13)
   Debug.Str(String("Value="))
   Debug.Dec(O & %1111111)
   Debug.Str(String(" ",13) )
   Debug.Str(String("Device="))
   Debug.Dec(O>>7 & %11111)
   'WaitCnt (Cnt+1_000_000)  
      
Dat

Entry                   ORG 0


                        Mov     Temp1,  Par
                        Mov     PAddr,  Temp1
                        Add     Temp1,  #4
                        Mov     OAddr,  Temp1
                        Add     Temp1,  #4
                        Mov     DAddr,  Temp1

                        RdLong  Pin,    PAddr
                        RdLong  PinMode,PAddr
                        
                        mov     Pin,    #1      wz              '  Configure DataPin
                        shl     Pin,    PinMode
                        muxz    dira,   Pin                     '  Set Pin as Input

                        Mov     CTRA,   #0
                        Mov     CTRA,   CntrModeIn              '  Logic !A
                        Movs    CTRA,   PinMode                 '  Input Pin Number
                        Mov     Frqa,   #1                      '  PHSA + 1    

Loop
                         
                        Call #Pulse                             '  Get Input Pulse From Pin
                        
                        CMP Duration,PStart WC                  '  Is pulse a Start Pulse??
              IF_AE     Call #Start                             '  If Yes Then Start Reading
                        JMP  #Loop                              '  If No then Wait for good Start Pulse
Start
                        Mov     Sample,Reset                    '  Grab 20 Pulses 
:Loop
                        Call    #Pulse                          '  If Pulse is Between Low and High
                        CMP     Duration,PLowBit WC             '  Set Bit = #0
              IF_AE     CMP     Duration,PHighBit WC  
              IF_B      or      Data,#0                 
              IF_B      JMP     #:Skip          

                        CMP     Duration,PHighBit WC            '  If Pulse is Between High and Start
              IF_AE     CMP     Duration,PStart WC              '  Set Bit = #1
              IF_B      or      Data,#1
:SKIP                   
                     
                        Shl     Data,#1                         '  Shift Into Data Register
                        
              
                        DJNZ    Sample,#:Loop                   '  Repeat until all 20 bits are accumulated
                        
                        Rev     Data,#11                        '  Put bits in proper order
                        WRLong  Data,OAddr                      '  Send to Spin
                        
Start_Ret               Ret 

PULSE                   WaitPNE Pin,Pin                         ' Grab Pulse on Input PIN
                        Mov     PHSA,#0
                        WaitPEQ Pin,Pin
                        WaitPNE Pin,Pin
                           
                        Mov     Duration,PHSA                    'Accumulate PHSA
PULSE_RET               RET
  
Pin                     Long    0
PinMode                 Long    0                                                                
PAddr                   Long    0                                                                      
OAddr                   Long    0                                               'Back to Spin Address
DAddr                   Long    0

CNTRModeOut             Long    (%00100 << 26 ) | (%001 << 23) | (0 << 9)          'NCO
FmodeOut                Long    %1_1111_0010_0001_0010_1101                        '38KHZ
CNTRModeIn              Long    (%10101 << 26 ) | (%010 << 23) | (0 << 9)          'Logic !A
                                                  
Temp1                   Long    0
 
 
Duration                Long    0        

PStart                  Long    190_000
PLowBit                 Long    50_000
PHighBit                Long    90_000
Sample                  Long    0
Reset                   Long    20

Data                    Long    0

JonnyMac

I wrote Sony decoding and encoding objects for my January column. Have a look at the code -- perhaps you'll find something useful.

SailerMan

Thanks as always. I wrote mine without looking at any other code... Now that I look at yours I like how you move the Carry bit into the right. Thanks for all of the code..

JonnyMac

You'll note, too, that my rx object allows for any valid SIRCS code -- it's not fixed at 20 bits. I have a Sony TV/DVD remote that mixes 12- and 20-bit commands so it's important to discriminate them. If you follow the code you'll see that my program allows for bits to come in for 44ms; the Sony spec says that a code should be transmitted in 45. I use 44 to give a little time (more than I need, really) to clean-up and report what was just received to the hub.

SailerMan

Yes I see that with the CheckFrame... It took me a little bit of time to figure out what you were doing.. From the start Bit you are accepting all bits until CheckFrame times out or 20bits.. I like it! [noparse]:)[/noparse]

JonnyMac

Exactly. When waiting for the start of a new frame a falling edge (start of new bit) resets the frame timer; if this bit is in fact a start bit then the code keeps going, otherwise the code tries again. What this means is that the 44ms window starts at the leading edge of the start bit. What I like is being able to use one counter in free run mode (frame timer) and the other in negative detect mode (bit width measurement); makes the code pretty darn easy, I think.

SailerMan

I agree... Even the code I wrote that is stuck in 20 bit mode was fairly easy to write for a beginner like me it was good practice.. I am going to continue to improve me code for learning purposes... I don't want to duplicate yours.. but I like the guidance.

Thanks,
Eric

PS I'm not sure if you remember instructing me on the SX... Two motor controller... I've decided to move my ASM efforts to the Propeller. Your help back a few months helped a great deal

Graham Stabler

I noticed something, you clear ctra and then immediately initialise it with mov, so no need to clear it first, you wasted four clock cycles [noparse]:)[/noparse] :O

Looks like you are doing great.

Graham

SailerMan

Thanks Graham... those are the things I'm looking for... Much appreciated.