Mercurial > hg > index.cgi

comparison docs/manual/x221.html @ 333:507f442dc71e

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Add support for 6800 compatibility instructions. The occasional program uses the 6800 compatibility instructions since they are actually specified by Motorola in at least some documentation. They advertised the 6809 as source compatible with the 6800. This mode is not enabled by default, however. It is my belief that receiving an error when using a non-6809 instruction is more useful since it is unlikely that much 6800 source code is being assembled for the 6809 these days. Nevertheless, the --6809compat option is present for just those purposes so one does not have to resort to using macros (which would work equally well in most cases).
author William Astle <lost@l-w.ca>
date Tue, 15 Apr 2014 10:57:34 -0600
parents
children
comparison
equal deleted inserted replaced
332:26bfe8d557e2 333:507f442dc71e
1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
2 <HTML
3 ><HEAD
4 ><TITLE
5 >Numbers and Expressions</TITLE
6 ><META
7 NAME="GENERATOR"
8 CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
9 REL="HOME"
10 TITLE="LW Tool Chain"
11 HREF="index.html"><LINK
12 REL="UP"
13 TITLE="LWASM"
14 HREF="c62.html"><LINK
15 REL="PREVIOUS"
16 TITLE="Symbols"
17 HREF="x216.html"><LINK
18 REL="NEXT"
19 TITLE="Assembler Directives"
20 HREF="x229.html"></HEAD
21 ><BODY
22 CLASS="SECTION"
23 BGCOLOR="#FFFFFF"
24 TEXT="#000000"
25 LINK="#0000FF"
26 VLINK="#840084"
27 ALINK="#0000FF"
28 ><DIV
29 CLASS="NAVHEADER"
30 ><TABLE
31 SUMMARY="Header navigation table"
32 WIDTH="100%"
33 BORDER="0"
34 CELLPADDING="0"
35 CELLSPACING="0"
36 ><TR
37 ><TH
38 COLSPAN="3"
39 ALIGN="center"
40 >LW Tool Chain</TH
41 ></TR
42 ><TR
43 ><TD
44 WIDTH="10%"
45 ALIGN="left"
46 VALIGN="bottom"
47 ><A
48 HREF="x216.html"
49 ACCESSKEY="P"
50 >Prev</A
51 ></TD
52 ><TD
53 WIDTH="80%"
54 ALIGN="center"
55 VALIGN="bottom"
56 >Chapter 3. LWASM</TD
57 ><TD
58 WIDTH="10%"
59 ALIGN="right"
60 VALIGN="bottom"
61 ><A
62 HREF="x229.html"
63 ACCESSKEY="N"
64 >Next</A
65 ></TD
66 ></TR
67 ></TABLE
68 ><HR
69 ALIGN="LEFT"
70 WIDTH="100%"></DIV
71 ><DIV
72 CLASS="SECTION"
73 ><H1
74 CLASS="SECTION"
75 ><A
76 NAME="AEN221"
77 >3.5. Numbers and Expressions</A
78 ></H1
79 ><P
80 >&#13;Numbers can be expressed in binary, octal, decimal, or hexadecimal. Binary
81 numbers may be prefixed with a "%" symbol or suffixed with a "b" or "B".
82 Octal numbers may be prefixed with "@" or suffixed with "Q", "q", "O", or
83 "o". Hexadecimal numbers may be prefixed with "$", "0x" or "0X", or suffixed
84 with "H". No prefix or suffix is required for decimal numbers but they can
85 be prefixed with "&amp;" if desired. Any constant which begins with a letter
86 must be expressed with the correct prefix base identifier or be prefixed
87 with a 0. Thus hexadecimal FF would have to be written either 0FFH or $FF.
88 Numbers are not case sensitive.&#13;</P
89 ><P
90 > A symbol may appear at any point where a number is acceptable. The
91 special symbol "*" can be used to represent the starting address of the
92 current source line within expressions. </P
93 ><P
94 >The ASCII value of a character can be included by prefixing it with a
95 single quote ('). The ASCII values of two characters can be included by
96 prefixing the characters with a quote (").</P
97 ><P
98 >&#13;LWASM supports the following basic binary operators: +, -, *, /, and %.
99 These represent addition, subtraction, multiplication, division, and
100 modulus. It also supports unary negation and unary 1's complement (- and ^
101 respectively). It is also possible to use ~ for the unary 1's complement
102 operator. For completeness, a unary positive (+) is supported though it is
103 a no-op. LWASM also supports using |, &#38;, and ^ for bitwise or, bitwise and,
104 and bitwise exclusive or respectively.&#13;</P
105 ><P
106 >&#13;Operator precedence follows the usual rules. Multiplication, division, and
107 modulus take precedence over addition and subtraction. Unary operators take
108 precedence over binary operators. Bitwise operators are lower precdence
109 than addition and subtraction. To force a specific order of evaluation,
110 parentheses can be used in the usual manner.&#13;</P
111 ><P
112 >&#13;As of LWASM 2.5, the operators &#38;&#38; and || are recognized for boolean and and
113 boolean or respectively. They will return either 0 or 1 (false or true).
114 They have the lowest precedence of all the binary operators.&#13;</P
115 ></DIV
116 ><DIV
117 CLASS="NAVFOOTER"
118 ><HR
119 ALIGN="LEFT"
120 WIDTH="100%"><TABLE
121 SUMMARY="Footer navigation table"
122 WIDTH="100%"
123 BORDER="0"
124 CELLPADDING="0"
125 CELLSPACING="0"
126 ><TR
127 ><TD
128 WIDTH="33%"
129 ALIGN="left"
130 VALIGN="top"
131 ><A
132 HREF="x216.html"
133 ACCESSKEY="P"
134 >Prev</A
135 ></TD
136 ><TD
137 WIDTH="34%"
138 ALIGN="center"
139 VALIGN="top"
140 ><A
141 HREF="index.html"
142 ACCESSKEY="H"
143 >Home</A
144 ></TD
145 ><TD
146 WIDTH="33%"
147 ALIGN="right"
148 VALIGN="top"
149 ><A
150 HREF="x229.html"
151 ACCESSKEY="N"
152 >Next</A
153 ></TD
154 ></TR
155 ><TR
156 ><TD
157 WIDTH="33%"
158 ALIGN="left"
159 VALIGN="top"
160 >Symbols</TD
161 ><TD
162 WIDTH="34%"
163 ALIGN="center"
164 VALIGN="top"
165 ><A
166 HREF="c62.html"
167 ACCESSKEY="U"
168 >Up</A
169 ></TD
170 ><TD
171 WIDTH="33%"
172 ALIGN="right"
173 VALIGN="top"
174 >Assembler Directives</TD
175 ></TR
176 ></TABLE
177 ></DIV
178 ></BODY
179 ></HTML
180 >