Abstract for ESA/XC Principles of Operation

This document provides a detailed description of the IBM® Enterprise Systems Architecture/Extended Configuration (ESA/XC) virtual-machine architecture, as provided by z/VM®. It describes the way an ESA/XC virtual machine operates as it appears to an assembler language programmer. Because ESA/XC is based on and is closely related to Enterprise Systems Architecture/390® (ESA/390), this document defines ESA/XC by indicating the ways in which it is the same as, or different from, ESA/390.

The following elements of the ESA/XC architecture are covered in this document:
  • Overall organization
  • The structure of storage and address spaces
  • Control facilities
  • Program execution
  • Interruptions
  • The operation of instructions
  • Input/output facilities

Intended Audience. This document is intended for programmers who write or debug programs that run in ESA/XC virtual machines.

You should have a basic familiarity with the ESA/390 architecture, or alternatively, the Enterprise Systems Architecture/370™ (ESA/370) or System/370 Extended Architecture (370-XA) upon which ESA/390 is based. These architectures are described in:
  • IBM Enterprise Systems Architecture/390 Principles of Operation, SA22-7201
  • IBM Enterprise Systems Architecture/370 Principles of Operation, SA22-7200
  • IBM System/370 Extended Architecture Principles of Operation, SA22-7085

You should also know IBM basic assembler language and have experience with z/VM programming concepts and techniques.

Conventions. This document is intended to be used in conjunction with the definition of ESA/390 provided in IBM Enterprise Systems Architecture/390 Principles of Operation. Where possible, information is presented in this document using the same style and general organization as IBM Enterprise Systems Architecture/390 Principles of Operation. To assist in locating corresponding information in the two documents, the following table shows the relationship of the chapters of this document to the chapters in IBM Enterprise Systems Architecture/390 Principles of Operation.

Chapter in this document Corresponding chapter(s) in IBM Enterprise Systems Architecture/390 Principles of Operation, SA22-7201-08
Introduction Chapter 1, Introduction
Organization Chapter 2, Organization
Storage Chapter 3, Storage
Control Chapter 4, Control
Program Execution Chapter 5, Program Execution
Interruptions Chapter 6, Interruptions
Instructions Chapter 7, General Instructions Chapter 8, Decimal Instructions Chapter 9, Floating-Point Overview and Support Instructions Chapter 10, Control Instructions Chapter 18, Hexadecimal-Floating-Point Instructions Chapter 19, Binary-Floating-Point Instructions
Machine-Check Handling Chapter 11, Machine-Check Handling
Input/Output Chapter 13, I/O Overview Chapter 14, I/O Instructions Chapter 15, Basic I/O Functions Chapter 16, I/O Interruptions Chapter 17, I/O Support Functions
Note: There is no material in this document corresponding to Chapter 12, Operator Facilities of IBM Enterprise Systems Architecture/390 Principles of Operation.