Intel 8080, 8085 manual Assembler Files, Symbol-Cross-Reference File

Page 9

8080/8085 Assembler

Assembler Overview

Symbol-Cross-Reference File

During the first pass of the assembler, a file of symbol-cross-reference records is created, if requested. This diskette file is named ASXREF.TMP .

In general, the assembler generates two types of symbol-cross-reference records: symbol-definition records and symbol-reference records. If a symbol appears as a name in a label field and the symbol is being defined (by SET, EQU, MACRO, or as a label), a symbol-definition record is produced. If the symbol is being redefined by SET or MACRO, it is considered a symbol definition. All other symbol occurrences are considered references and cause the assembler to generate a symbol-reference record each time the symbol appears. Symbol definition records are terminated by a pound sign (##) in the cross-reference listing.

All symbols are cross referenced except dummy parameters and local labels appear- ing in macro definitions (that is, all global user-defined symbols, macro names, and actual symbols replacing dummy parameters or local labels are cross referenced). When certain controls that suppress source listing are specified (NOLIST, NOGEN, NOCOND), symbols not listed are not cross referenced.

The assembler calls on ISIS-II to load its cross-reference-generator program and ASXREF.TMP from the diskette. From the programmer's point of view, the opera- tions required to produce the cross-reference listing are automatic (once the cross reference file has been requested). The format of the cross-reference listing is shown in Chapter 4.

Assembler Files

The ISIS-II assembler uses several files of its own, such as the intermediate cross- reference file just mentioned. While you don't need to remember the names of these files, you must know where they reside to avoid diskette space conflict.

The assembler root program (ASM80) and its overlays (ASM80.0Vn, where n=O, 1,2...) must reside on the same diskette, but this diskette can be on any drive. The cross-reference generator (ASXREF) must reside on this diskette also.

The intermediate cross-reference file (ASXREF. TMP) is written to the drive con- taining your source file. The MACROFILE control determines where the in- termediate macro file (ASMAC. TMP) is written; the default is the source file drive.

The list and object files can be directed to any drive via assembler controls. The default sends these files to the source file drive.

1-3

Image 9
Contents ISIS-II 8080/8085 Macro Assembler Operatorsmanual Scope Prefacei Page Contentsi Page ISIS-II Assembler Environment Chapter Assembler OverviewInput/Output Files Assembler Files Symbol-Cross-Reference FilePage Chapter ISIS·IIAssembler Controls Primary Controls General Controls ISIS-II Assembler Control Lines Page Activation Sequence Sample AssemblyAsmbo MBADD.SRC Symbols Xref Macrofile Reducing Assembly Time Page Chapter List File Formats List File Formats 808O/808S Assembler Assembly Output Line Symbol Table Listing Cross-Reference Output Line Symbol-Cross-Reference ListingChapter PL/M Linkage Conventions Page Relocatable Programs Absolute ProgramsPage Error Codes Error Detection and ReportingError Messqes ISIS-II Error Messages FOCC= OOnn Request for Readerscomments 111111
Related manuals
Manual 96 pages 34.66 Kb Manual 262 pages 56.67 Kb Manual 160 pages 43.4 Kb

8080, 8085 specifications

The Intel 8085 and 8080 microprocessors were groundbreaking innovations in the world of computing, paving the way for future microprocessor development and personal computing.

The Intel 8080, introduced in 1974, was an 8-bit microprocessor that played a fundamental role in the early days of personal computing. With a 16-bit address bus, it had the capability to address 64 KB of memory. Running at clock speeds of 2 MHz, the 8080 was notable for its instruction set, which included 78 instructions and 246 opcodes. It supported a range of addressing modes including direct, indirect, and register addressing. The 8080 was compatible with a variety of peripherals and played a crucial role in the development of many early computers.

The microprocessor's architecture was based on a simple and efficient design, making it accessible for hobbyists and engineers alike. It included an 8-bit accumulator, which allowed for data manipulation and storage during processing. Additionally, the 8080 featured registers like the program counter and stack pointer, which facilitated program flow control and data management. Its ability to handle interrupts also made it suitable for multitasking applications.

The Intel 8085, introduced in 1976, was an enhancement of the 8080 microprocessor. It maintained a similar architecture but included several key improvements. Notably, the 8085 had a built-in clock oscillator, simplifying system design by eliminating the need for external clock circuitry. It also featured a 5-bit control signal for status line management, which allowed for more flexible interfacing with peripheral devices. The 8085 was capable of running at speeds of up to 3 MHz and had an extended instruction set with 74 instructions.

One of the standout features of the 8085 was its support for 5 extra instructions for stack manipulation and I/O operations, which optimized the programming process. Additionally, it supported serial communication, making it suitable for interfacing with external devices. Its 16-bit address bus retained the 64 KB memory addressing capability of its predecessor.

Both the 8080 and 8085 microprocessors laid the groundwork for more advanced microprocessors in the years that followed. They demonstrated the potential of integrated circuits in computing and influenced the design and architecture of subsequent Intel microprocessors. Their legacy endures in the way they revolutionized computing, making technology accessible to a broader audience, and their influence is still felt in the design and architecture of modern microprocessors today.