Programming the 65816 Including the 6502, 65C02 and 65802 Distributed and published under COPYRIGHT LICENSE AND PUBLISHING AGREEMENT with Authors David Eyes and Ron Lichty EFFECTIVE APRIL 28, 1992 Copyright © 2007 by The Western Design Center, Inc. 2166 E. Brown Rd. Mesa, AZ 85213 480-962-4545 (p) 480-835-6442 (f) www.westerndesigncenter.com The Western Design Center Table of Contents 1) Chapter One .......................................................................................................... 12 Basic Assembly Language Programming Concepts..................................................................................12 Binary Numbers.................................................................................................................................................... 12 Grouping Bits into Bytes....................................................................................................................................... 13 Hexadecimal Representation of Binary................................................................................................................ 14 The ACSII Character Set ..................................................................................................................................... 15 Boolean Logic........................................................................................................................................................ 16 Logical And........................................................................................................................................................ 16 Logical Or .......................................................................................................................................................... 17 Logical Exclusive Or........................................................................................................................................... 17 Logical Complement........................................................................................................................................... 17 Signed Numbers .................................................................................................................................................... 18 Storing Numbers in Decimal Form....................................................................................................................... 19 Computer Arithmetic............................................................................................................................................ 20 Microprocessor Programming.............................................................................................................................. 20 Machine Language.............................................................................................................................................. 20 Assembly Language............................................................................................................................................ 22 Writing in Assembly Language ............................................................................................................................ 22 Basic Programming Concepts............................................................................................................................... 23 Selection Between Paths...................................................................................................................................... 24 Looping .............................................................................................................................................................. 24 Subroutines......................................................................................................................................................... 24 2) Chapter Two.......................................................................................................... 26 Architecture of the 6502 ............................................................................................................................26 Microprocessor Architecture................................................................................................................................ 26 The 6502 Registers ................................................................................................................................................ 26 The Accumulator ................................................................................................................................................ 27 The X and Y Index Registers............................................................................................................................... 29 The Status Register ............................................................................................................................................. 29 Abbrev................................................................................................................................................................ 30 Name.................................................................................................................................................................. 31 The Stack Pointer................................................................................................................................................ 31 The Program Counter.......................................................................................................................................... 33 Addressing Modes................................................................................................................................................. 33 Instructions ........................................................................................................................................................... 35 The 6502 System Design........................................................................................................................................ 38 Pipelining ........................................................................................................................................................... 38 Memory Order of Multiple-Byte Values .............................................................................................................. 39 Memory-Mapped Input/Output............................................................................................................................ 39 Interrupts ............................................................................................................................................................ 39 NMOS Process ...................................................................................................................................................... 40 Bugs and Quirks ................................................................................................................................................... 40 3) Chapter Three ....................................................................................................... 41 Architecture of the 65C02 .........................................................................................................................41 The 65C02 Architecture........................................................................................................................................ 41 Addressing Modes................................................................................................................................................. 41 Instructions ........................................................................................................................................................... 42 CMOS Process ...................................................................................................................................................... 42 Bugs and Quirks ................................................................................................................................................... 42 4) Chapter Four......................................................................................................... 44 Sixteen-Bit Architecture The 65816 and the 65802...................................................................................44 2 The Western Design Center Power-On Status: 6502 Emulation Mode..................................................................................................45 The Full-Featured 65x Processor: The 65816 in Native Mode ................................................................45 The Program Bank Register ................................................................................................................................. 47 The Data Bank Register........................................................................................................................................ 48 The Direct Page Register ...................................................................................................................................... 48 The Stack Pointer.................................................................................................................................................. 48 Accumulator and Index Registers ........................................................................................................................ 48 Switching Registers