In SX Microcontrollers, SX/B Compiler and SX-Key Tool, dkemppai wrote:

Be patient...That's less than a day, not everyone who uses the SX gets on that much.  I'm sure someone has tried it.


[/quote]
 


 

 

Yeah, I'm guess I'm just starting to get impatient...   ...I posed the following code snippit over a month ago dealing with my first issue.  No one appears to have looked at it since then.  

 

Anyway, I was trying to get someone to try this code with SOURCING curent to an LED and oscilloscope on the RB.0 pin. 

 

Try it...    ...You'll be confused if you look into the datasheet/app notes for reset conditions. Then try it with the ";  MOV  RB, SHADOW" uncommented. You would think, that in both cases the LED would flash at about 4 second rate, with a roughtly 50% duty cycle...   ...anyway. It won't. It only works with the shadow register enabled. As posted, the code will only generate a 3.800uS wide 'glitch' on the output pin. With the shadow move enabled, it works as expected. 

 

Oh, yeah, you can add some nop's around the "READ MODIFY WRITE"'s to prevent additional glitches...

 

 

-Dan

 

----------------Code example------------------------

  

 

NOCASE   ;No Case Sensitive ASM
  DEVICE SX28L  ;28 pin chip
  DEVICE  OSCXT1
  DEVICE BOR22  ;Brownout at 2.2Volts
  IRC_CAL IRC_FAST ;(Faster programming)   
  DEVICE STACKX  ;Use the Extended Stack.
  DEVICE  IFBD  ;Disable Internal Feedback.
  DEVICE  TURBO  ;Turbo Mode
  DEVICE WATCHDOG ;Enable Watchdog timer.
  
  FREQ 4_000_000          ;START WITH A XXMHz Clock
 
RESET Main
org $08
counter DS  3
SHADOW DS 1
Main

;  MOV  RB, SHADOW
    MODE $0F   ;Mode for Direction Registers
    MOV  !RA, #%0000  ;0 = output, 1 = input
    MOV  !RC, #%00000000   
    MOV  !RB, #%00000000 
    MOV  !option, #%11111111 
  
  ;Check to see if Start is from WatchDog timeout. 
    MOV W,status
    AND W,#%00011000 ;Bits TO = 0 and PD = 0 on WDT reset.
    JZ WDTStart ;Skip Following code on WatchDog Reset
    ;Place code to be skipped on WDT reset here... 

 

WDTStart  JB  RB.0,:clrbit  
  SETB  RB.0  
  jmp :bitdne
:clrbit  clrb  RB.0
  nop
:bitdne 
 
    CLR  !WDT
    MOV SHADOW, RB
  SLEEP

---------- End of Message ----------


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