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

Welp, I just hit 19 Variables on the SX28 and wanted to add some more functionality.

 

Referencing the help file on Variables, I'm seeing:

 


[table  cellSpacing=0 cellPadding=4 border=1]
[tr  bgColor=#cfcfcf][td  align=left width=75]Device[/td][td  align=middle width=75]General[/td][td  align=middle width=125]Arrays[/td][td  align=middle width=75]Max. Array[/td][/tr][tr ][td  align=left] SX18/20[/td][td  align=middle]20[/td][td  align=middle]6x16 + 1x5 + 1x4[/td][td  align=middle]16 (each)[/td][/tr][tr ][td  align=left] SX28[/td][td  align=middle]19[/td][td  align=middle]6x16 + 1x5 + 1x4[/td][td  align=middle]16 (each)[/td][/tr][tr ][td  align=left] SX48/52[/td][td  align=middle]17[/td][td  align=middle]223[/td][td  align=middle]223[/td][/tr][/table]

Looking at my code I have:

<UL>
* 6 Word Variables = 12 Bytes

* 7 Byte Variables

* 3 element Array of type Byte

* 3 I/O Ports
</UL>
So, as far as from what I've read from [url=http://forums.parallax.com/forums/default.aspx?f=7&amp;m=146212]SX/B RAM Banking Scheme[/url], I'm understanding that now I would need to use arrays and an alias for any other variables.  

 

[b]1.  How do I determine how much variable space do I have left?[/b]


Mapping out the remaining space, I was curious how are I/O ports part of the variable mapping, and how much actual variable space I have left:

It looks like I have the following available:

<UL>
* 1X5

* 1X1 (using 3 elements of the 1X4)

* 6X16  &gt; Is this where the max 16 comes from in the table?
</UL>

[b]2.  In the case of aliasing,  shouldn't they function as a regular variable?[/b] 



[code]myValue Word
index VAR byte(3) 
i VAR index(0) 
j VAR index(1) 
k VAR index(2) 

  

j = 3 

Lookup j, CON1, CON2, CON3, CON4, CON5, CON6, myValue 


When I comple this, I get a 'BYTE VARIABLE EXPECTED: "j"' error.
 3.  Within my program, have a a incrementing counter.   Based on that counter, I want to lookup a position for a predefined address label, and use it in the read statement later on in my programm. 


I initially tried using the WDATA statement, as in



[code]
WDATA LABEL1, LABEL2, LABEL3, LABEL4, LABEL5 
[/code]

The compiler didn't like it.  Should this work?

 

In finding an alternative, I used a real byte instead of an array, on #2 above, 

 



[code]
myValue VAR Word 

i VAR Byte 

  

i = 3 

LOOKUP i, LABEL1, LABEL2, LABEL3, LABEL4, LABEL5, myValue 


The compiler liked it better, but still complains with the following:

<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
 Warning 73, Pass 2: Mulit-byte instruction following skip instruction.  

Looking at the assembly shows that it looks like it's doing what I want.  Is there any concern?

</BLOCKQUOTE>
Is there another alternative, to do what I want to do other than multiple if-then's?  Branching won't work since I don't actually want to execute the code at the addresses.

 

 

Thanks!

 

Rodney

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