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1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
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2 <HTML
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3 ><HEAD
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4 ><TITLE
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5 >Numbers and Expressions</TITLE
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6 ><META
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7 NAME="GENERATOR"
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8 CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
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9 REL="HOME"
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10 TITLE="LW Tool Chain"
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11 HREF="index.html"><LINK
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12 REL="UP"
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13 TITLE="LWASM"
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14 HREF="c43.html"><LINK
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15 REL="PREVIOUS"
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16 TITLE="Symbols"
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17 HREF="x168.html"><LINK
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18 REL="NEXT"
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19 TITLE="Assembler Directives"
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20 HREF="x181.html"></HEAD
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21 ><BODY
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22 CLASS="SECTION"
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23 BGCOLOR="#FFFFFF"
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24 TEXT="#000000"
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25 LINK="#0000FF"
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26 VLINK="#840084"
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27 ALINK="#0000FF"
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28 ><DIV
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29 CLASS="NAVHEADER"
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30 ><TABLE
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31 SUMMARY="Header navigation table"
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32 WIDTH="100%"
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33 BORDER="0"
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34 CELLPADDING="0"
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35 CELLSPACING="0"
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36 ><TR
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37 ><TH
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38 COLSPAN="3"
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39 ALIGN="center"
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40 >LW Tool Chain</TH
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41 ></TR
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42 ><TR
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43 ><TD
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44 WIDTH="10%"
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45 ALIGN="left"
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46 VALIGN="bottom"
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47 ><A
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48 HREF="x168.html"
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49 ACCESSKEY="P"
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50 >Prev</A
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51 ></TD
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52 ><TD
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53 WIDTH="80%"
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54 ALIGN="center"
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55 VALIGN="bottom"
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56 >Chapter 3. LWASM</TD
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57 ><TD
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58 WIDTH="10%"
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59 ALIGN="right"
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60 VALIGN="bottom"
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61 ><A
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62 HREF="x181.html"
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63 ACCESSKEY="N"
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64 >Next</A
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65 ></TD
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66 ></TR
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67 ></TABLE
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68 ><HR
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69 ALIGN="LEFT"
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70 WIDTH="100%"></DIV
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71 ><DIV
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72 CLASS="SECTION"
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73 ><H1
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74 CLASS="SECTION"
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75 ><A
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76 NAME="AEN173"
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77 >3.5. Numbers and Expressions</A
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78 ></H1
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79 ><P
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80 > Numbers can be expressed in binary, octal, decimal, or hexadecimal. Binary
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81 numbers may be prefixed with a "%" symbol or suffixed with a "b" or "B".
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82 Octal numbers may be prefixed with "@" or suffixed with "Q", "q", "O", or
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83 "o". Hexadecimal numbers may be prefixed with "$", "0x" or "0X", or suffixed
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84 with "H". No prefix or suffix is required for decimal numbers but they can
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85 be prefixed with "&" if desired. Any constant which begins with a letter
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86 must be expressed with the correct prefix base identifier or be prefixed
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87 with a 0. Thus hexadecimal FF would have to be written either 0FFH or $FF.
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88 Numbers are not case sensitive. </P
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89 ><P
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90 > A symbol may appear at any point where a number is acceptable. The
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91 special symbol "*" can be used to represent the starting address of the
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92 current source line within expressions. </P
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93 ><P
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94 >The ASCII value of a character can be included by prefixing it with a
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95 single quote ('). The ASCII values of two characters can be included by
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96 prefixing the characters with a quote (").</P
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97 ><P
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98 > LWASM supports the following basic binary operators: +, -, *, /, and %.
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99 These represent addition, subtraction, multiplication, division, and
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100 modulus. It also supports unary negation and unary 1's complement (- and ^
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101 respectively). It is also possible to use ~ for the unary 1's complement
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102 operator. For completeness, a unary positive (+) is supported though it is
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103 a no-op. LWASM also supports using |, &, and ^ for bitwise or, bitwise and,
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104 and bitwise exclusive or respectively. </P
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105 ><P
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106 > Operator precedence follows the usual rules. Multiplication, division, and
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107 modulus take precedence over addition and subtraction. Unary operators take
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108 precedence over binary operators. Bitwise operators are lower precdence
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109 than addition and subtraction. To force a specific order of evaluation,
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110 parentheses can be used in the usual manner. </P
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111 ><P
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112 > As of LWASM 2.5, the operators && and || are recognized for boolean and and
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113 boolean or respectively. They will return either 0 or 1 (false or true).
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114 They have the lowest precedence of all the binary operators. </P
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115 ></DIV
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116 ><DIV
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117 CLASS="NAVFOOTER"
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118 ><HR
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119 ALIGN="LEFT"
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120 WIDTH="100%"><TABLE
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121 SUMMARY="Footer navigation table"
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122 WIDTH="100%"
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123 BORDER="0"
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124 CELLPADDING="0"
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125 CELLSPACING="0"
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126 ><TR
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127 ><TD
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128 WIDTH="33%"
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129 ALIGN="left"
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130 VALIGN="top"
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131 ><A
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132 HREF="x168.html"
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133 ACCESSKEY="P"
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134 >Prev</A
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135 ></TD
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136 ><TD
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137 WIDTH="34%"
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138 ALIGN="center"
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139 VALIGN="top"
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140 ><A
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141 HREF="index.html"
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142 ACCESSKEY="H"
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143 >Home</A
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144 ></TD
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145 ><TD
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146 WIDTH="33%"
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147 ALIGN="right"
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148 VALIGN="top"
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149 ><A
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150 HREF="x181.html"
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151 ACCESSKEY="N"
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152 >Next</A
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153 ></TD
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154 ></TR
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155 ><TR
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156 ><TD
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157 WIDTH="33%"
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158 ALIGN="left"
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159 VALIGN="top"
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160 >Symbols</TD
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161 ><TD
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162 WIDTH="34%"
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163 ALIGN="center"
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164 VALIGN="top"
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165 ><A
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166 HREF="c43.html"
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167 ACCESSKEY="U"
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168 >Up</A
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169 ></TD
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170 ><TD
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171 WIDTH="33%"
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172 ALIGN="right"
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173 VALIGN="top"
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174 >Assembler Directives</TD
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175 ></TR
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176 ></TABLE
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177 ></DIV
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178 ></BODY
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179 ></HTML
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180 > |
