Lecture Microcomputer principles and applications - Chapter 3: Assembly language programming

Chapter 3<br /> Assembly language<br /> programming<br /> <br /> 3.1 Introduction to Assembly<br /> High level vs. Assembly<br /> High level languages<br /> • More programmer friendly.<br /> • More ISA independent.<br /> • Each high-level statement<br /> translates to several instructions<br /> in the ISA of the computer.<br /> <br /> Assembly language<br /> • Lower level, closer to ISA.<br /> • Very ISA-dependent.<br /> • Each instruction specifies a<br /> single ISA instruction.<br /> • Makes low level programming<br /> more user friendly.<br /> • More efficient code.<br /> <br /> Microcomputer principles and applications<br /> <br /> 3.1 Introduction to Assembly<br /> Assembler syntax<br /> <br /> {label[:]} mnemonic {operand list} {;comment}<br /> •<br /> <br /> Symbols:<br /> ⋄<br /> ⋄<br /> <br /> ⋄<br /> •<br /> <br /> Used as labels, constants, and substitution values and<br /> stored in a symbol table.<br /> A symbol name is a string of up to 200 alphanumeric<br /> characters (A-Z, a-z, 0-9, $, and _), cannot contain<br /> embedded blanks, is case sensitive.<br /> The first character cannot be a number.<br /> <br /> Labels:<br /> ⋄<br /> <br /> Labels are symbols.<br /> Microcomputer principles and applications<br /> <br /> 3.1 Introduction to Assembly<br /> Assembler syntax<br /> <br /> {label[:]} mnemonic {operand list} {;comment}<br /> •<br /> <br /> Labels:<br /> ⋄<br /> ⋄<br /> ⋄<br /> ⋄<br /> <br /> •<br /> <br /> Begined in column 1 and is optionally followed by a colon.<br /> The value of a label is the current value of the Location<br /> Counter (address within program).<br /> A label on a line by itself is a valid statement.<br /> Labels used locally within a file must be unique.<br /> <br /> Mnemonics:<br /> ⋄<br /> <br /> Cannot start in column 1. If it does, it is interpreted as a label.<br /> <br /> Microcomputer principles and applications<br /> <br /> 3.1 Introduction to Assembly<br /> Assembler syntax<br /> <br /> {label[:]} mnemonic {operand list} {;comment}<br /> •<br /> <br /> Mnemonics:<br /> ⋄<br /> ⋄<br /> ⋄<br /> <br /> •<br /> <br /> Contains one of the following items: Instruction, Assembler<br /> directive, Macro directive, Macro invocation.<br /> A label on a line by itself is a valid statement.<br /> Labels used locally within a file must be unique.<br /> <br /> Operands:<br /> ⋄<br /> ⋄<br /> ⋄<br /> <br /> Contains one or more operands.<br /> An operand may consist of: symbols, constants,<br /> expressions.<br /> Operands are separated with commas.<br /> Microcomputer principles and applications<br /> <br />