Z80 Microprocessors Z80 CPU User Manual UM008011-0816 Copyright ©2016 Zilog, Inc. All rights reserved. www.zilog.com Z80 CPU User Manual ii Warning: DO NOT USE THIS PRODUCT IN LIFE SUPPORT SYSTEMS. LIFE SUPPORT POLICY ZILOG’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF ZILOG CORPORATION. As used herein Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user. A criti- cal component is any component in a life support device or system whose failure to perform can be reason- ably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. Document Disclaimer ©2016 Zilog, Inc. All rights reserved. Information in this publication concerning the devices, applications, or technology described is intended to suggest possible uses and may be superseded. ZILOG, INC. DOES NOT ASSUME LIABILITY FOR OR PROVIDE A REPRESENTATION OF ACCURACY OF THE INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED IN THIS DOCUMENT. ZILOG ALSO DOES NOT ASSUME LIABILITY FOR INTELLECTUAL PROPERTY INFRINGEMENT RELATED IN ANY MANNER TO USE OF INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED HEREIN OR OTHERWISE. The information contained within this document has been verified according to the general principles of electrical and mechanical engineering. Z80, Z180, Z380 and Z80382 are trademarks or registered trademarks of Zilog, Inc. All other product or service names are the property of their respective owners. UM008011-0816 Z80 CPU User Manual iii Revision History Each instance in the following revision history table reflects a change to this document from its previous version. For more details, refer to the corresponding pages provided in the table. Revision Date Level Description Page Aug 11 Made formatting changes for better readability. 39, 40, 41 2016 Aug 10 Added Instruction Notation Summary; corrected typos and 39, 42, 123, 126, 136, 2016 errors 242, May 09 Corrected typos and errors. 126, 132, 133, 136, 141, 2016 192, 317 Jan 08 Corrected typos and errors. 46, 77, 103, 112, 122, 2016 130, 132, 138, 161, 207,221, 224, 227, 233, 253, 255, 263, 296 Jul 07 Corrected typos in POP qq description. 119 2015 Jul 06 Updated to Zilog style and to incorporate customer 65, 126 2014 suggestions, including a correction to the Z80 Status Indicator Flags table, bit 4, and a correction to the EXX instruction at bit 0. Feb 05 Corrected the hex code for the RLCA instruction; 55, 205 2005 corrected illustration for the Rotate and Shift Group RLCA instruction. Dec 04 Corrected discrepancies in the bit patterns for IM 0, IM 1 184, 185, 186 2004 and IM 2 instructions. UM008011-0816 Revision History Z80 CPU User Manual iv Revision History UM008011-0816 Z80 CPU User Manual v Table of Contents Revision History. .iii Table of Contents . v List of Figures. .xi List of Tables . .xiii Architectural Overview . 1 CPU Register . 2 Special-Purpose Registers . 2 General Purpose Registers . 3 Arithmetic Logic Unit . 4 Instruction Register and CPU Control . 4 Pin Functions . 5 Timing . 7 Instruction Fetch . 8 Memory Read Or Write . 9 Input or Output Cycles . 10 Bus Request/Acknowledge Cycle . 11 Interrupt Request/Acknowledge Cycle . 12 Nonmaskable Interrupt Response . 13 HALT Exit . 14 Power-Down Acknowledge Cycle . 15 Power-Down Release Cycle . 16 Interrupt Response . 17 Interrupt Enable/Disable . 17 CPU Response . 19 Hardware and Software Implementation . 21 Minimum System Hardware . 21 Adding RAM . 22 Memory Speed Control . 23 Interfacing Dynamic Memories . 25 Software Implementation Examples . 26 Specific Z80 Instruction Examples . 27 Programming Task Examples . 29 Z80 CPU Instructions. 32 Instruction Types . 32 UM008011-0816 Table of Contents Z80 CPU User Manual vi Addressing Modes . 34 Immediate Addressing . 34 Immediate Extended Addressing . 34 Modified Page Zero Addressing . 35 Relative Addressing . 35 Extended Addressing . 36 Indexed Addressing . 36 Register Addressing . 37 Implied Addressing . 37 Register Indirect Addressing . 37 Bit Addressing . 38 Addressing Mode Combinations . 38 Instruction Notation Summary . 39 Instruction Op Codes . 40 Load and Exchange . 41 Block Transfer and Search . 47 Arithmetic and Logical . 49 Rotate and Shift . 53 Bit Manipulation . 55 Jump, Call, and Return . 58 Input/Output . 61 CPU Control Group . 63 Z80 Instruction Set . 65 Z80 Assembly Language . 65 Z80 Status Indicator Flags . 65 Carry Flag . 66 Add/Subtract Flag . 66 Decimal Adjust Accumulator Flag . 67 Parity/Overflow Flag . 67 Half Carry Flag . ..