Code in PBPPI18L.LIB, can I ?

[amgen]

Trying to have ARRAYREAD read more than 255 chars and in LIB, R6, the max char counter is word and only used as byte for max parse.
Would changing the DECREMENT to 16 bit work without messing up something ?


ArrayRead in LIB 18L

;****************************************************************
;* ARRAYREAD  : Read char from array                            *
;*                                                              *
;* Input      : R5 = pointer to next char in array              *
;*            : R6 = number of chars left in array (timeout)    *
;* Output     : W                                               *
;*                                                              *
;* Notes      : C clear if timed out.                           *
;****************************************************************
    ifdef ARRAYREADTO_USED
  LIST
ARRAYREADTO movf R6, F        ; Check for no chars left in array
    bcf    STATUS, C    ; Preset for timed out (C clear)
    bz    arrayreaddone    ; No chars left
    decf    R6, F        ; Count down the characters left and fall through to ARRAYREAD
  NOLIST
ARRAYREAD_USED = 1
    endif

Code to DECREMENT 16 bit val,

The Decrement of a 16 Bit value isn't quite so simple: 
CODE

movf     Reg,  f                  ;Set "Z" if LOW "Reg" == 0
btfsc     STATUS,  Z 
decf      Reg + 1,  f            ; If Low byte is Zero, Decrement High
decf      Reg,  f

To make count up to 16bit

  To make count up to 16bit
　
  ifdef ARRAYREADTO_USED
  LIST
ARRAYREADTO movf R6, F        ; Check for no chars left in array
    bcf    STATUS, C    ; Preset for timed out (C clear)
    bz    arrayreaddone    ; No chars left

    movf     R6,  f                                       ; Set "Z" if LOW "Reg" == 0
                btfsc         STATUS,  Z 
                decf          R6 + 1,  f             ; If Low byte is Zero, Decrement High
                decf          R6,  f
  
  NOLIST
ARRAYREAD_USED = 1
    endif

I want to check with experts before I screw things up.
Thanks
Don
amgen

[amgen]

Are you even allowed to reply to your own thread. Seems like talking to yourself..Oh well....

Tried successfully to make MAX chars to word, although all you can have 500, 1000 or 2000 array depending on ram (I think),

;****************************************************************
;* ARRAYREAD  : Read char from array                            *
;*                                                              *
;* Input      : R5 = pointer to next char in array              *
;*            : R6 = number of chars left in array (timeout)    *
;* Output     : W                                               *
;*                                                              *
;* Notes      : C clear if timed out.                           *
;****************************************************************
    ifdef ARRAYREADTO_USED
  LIST
ARRAYREADTO movf R6, F        ; Check for no chars left in array
    bcf    STATUS, C       ; Preset for timed out (C clear)
    btfsc STATUS, Z
    movf  R6+1, F
    bz    arrayreaddone    ; No chars left
    
       movf   R6, F           ; Set "Z" if LOW "Reg" == 0
btfsc  STATUS, Z 
   decf  R6+1, F       ; If Low byte is Zero, Decrement High
     decf    R6, F           ; Count down the characters left and fall through to ARRAYREAD
  NOLIST
ARRAYREAD_USED = 1
    endif

arrayread arr1,500,done,[wait("123qwe")]

Don
(does anyone see redundent code ?)

[Darrel Taylor]

Well, I don't see redundant code. But there's probably not enough code.
I was running it in proteus and found that it stops reading the array whenever a borrow occurs from the high byte of R6.

At points like 1023, 767, 511, 255 bytes remaining, it exits the ARRAYREAD.

It uses the carry flag (STATUS,C) to indicate the "Timeout", which should only be cleared when both bytes are 0.

HTH,

[amgen]

Preface...... I think,

Max readarray would/could TRY to be 65K, (word)...... too long for any possible array to read in PIC.
So, is your check looping thru 64KB ??? (I assssume no one wants to parse flash)

example of my code

array1Test:    ' arr1 has INDX chars that is < ARR1[declared legnth]
Flag1=0
arrayread arr1,INDX,done,[wait("1qwe")]:Flag1=1 'found match
done:      'no match

My little array is 1000, and the arrayread matched the match anywhere from begining to the end.
But, I was wondering if a "MATCH-TO-EXIT" compare char code, could be added. Like arraywrite, then tested on each pass, without extensive code addition.

Then it would be;
ARRAYREAD array_to_read, max_legnth, compare_char_to_exit, escape_labl[.....xyz....]

As you stated somewhere, array read & write is making string usage much more practical.
Don

[amgen]

forget misinterpreted last post,
not sure if you saw,
In second post I had added the check for 16 bit =0,at top of routine, few lines asm for that

 LIST
ARRAYREADTO movf R6, F                       ; Check for no chars left in array    hi & low R6
                     bcf STATUS, C                   ; Preset for timed out (C clear)   
                     btfsc STATUS, Z          ; Set "Z" if LOW "Reg" == 0
                     movf  R6+1, F    
                     bz    arrayreaddone               ; No chars left
                     movf   R6, F                   
            btfsc  STATUS, Z      ;decrement high and low
           decf  R6+1, F         ;If Low byte is Zero, Decrement High
                      decf    R6, F                          ; Count down the characters left and fall through to ARRAYREAD  

NOLISTARRAYREAD_USED = 1    
endif

hard to format text in code window.
Don

[Darrel Taylor]

OK, and you can forget my misinterpreted last post too.
After further testing, your changes do work as advertised. My test was flawed.

Back to the redundant code question, I think you can save 1 WORD by changing the second part to ...

;        movf   R6, F
        decf    R6, F          ; Count down the characters left and fall through to ARRAYREAD  
        btfss  STATUS, C       ; If Low byte borrowed
        decf  R6+1, F          ; Decrement High

It's not much, but ...

[Darrel Taylor]

Don,

Would you like melabs to include your changes in the next update to PBP3?

[amgen]

By all means,
I would feel honored.

Don

[ShoKre]

Hi, I just seen this post, but i already post my problem regarding array.0(word-sized-variable)
as this isue is similar for reading, can someone give me hint how can we patch writing routine
to have array.0(word-sized-variable) working, as now only byte size index works....

regards, & thenx for any kind oh help