Slide 5.13: Calculating data sizes and EQU directive
Slide 6.1: Data transfer instructions
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TEXTEQU Directive
The TEXTEQU directive is very similar to EQU. It creates a text macro.   

 

 name  TEXTEQU  <text>
 

 name  TEXTEQU  textmacro
 

 name  TEXTEQU  %constExpr
Unlike EQU directive, a symbol defined with TEXTEQU can be redefined later in the program.

 name = expression  name EQU expression  name TEXTEQU %constExpr 
 

 Year  =  2002
 

 .data
 

 Year  =  2003
 

 .code
 

 Year  =  2004
 

 mov   eax, Year
 

 call  WriteInt
 
 

 Year  EQU  2002
 

 .data
 

 Year  EQU  2003
 

 .code
 

 Year  EQU  2004
 

 mov   eax, Year
 

 call  WriteInt
 
 

 Year  TEXTEQU  %2002
 

 .data
 

 Year  TEXTEQU  %2003
 

 .code
 

 Year  TEXTEQU  %2004
 

 mov   eax, Year
 

 call  WriteInt
 Output  Output  Output
   



   



   




 String Size by
name TEXTEQU <text> 		  Array Size by
name TEXTEQU textmacro 		 

 

 setEAX  TEXTEQU 
 

 .data
 

 string  BYTE  'A', 'B', 'C', 'D', 0
 

 len  EQU ($ - string)
 

 .code
 

 setEAX
 

 call  WriteInt
    


 

 .data
 

 array  WORD  10, 20, 30, 40, 50
 

 len = ($ - array) / 2
 

 .code
 

 setEAX  EQU 
 

 setupEAX  TEXTEQU  setEAX
 

 setupEAX
 

 call  WriteInt
   

 Output  Output
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