World Library  
Flag as Inappropriate
Email this Article

Intersil 6100

Article Id: WHEBN0020630062
Reproduction Date:

Title: Intersil 6100  
Author: World Heritage Encyclopedia
Language: English
Subject: PDP-8, 12-bit, Microprocessors, Digital Equipment Corporation, Microprocessor
Collection: Microprocessors
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Intersil 6100

The Intersil 6100 family consisted of a 12-bit microprocessor (the 6100) and a range of peripheral support and memory ICs developed by Intersil in the mid-1970s. The microprocessor recognised the PDP-8 instruction set. As such it was sometimes referred to as the CMOS-PDP8. Since it was also produced by Harris Corporation, it was also known as the Harris HM-6100. The Intersil 6100 was introduced in the second quarter of 1975,[1][2] and the Harris version in 1976.[2] By virtue of its CMOS technology and associated benefits, the 6100 was being incorporated into some military designs until the early 1980s.

The 6100 family was produced using CMOS rather than the bipolar and NMOS technologies used by its contemporaries (Z80, 8080, 6800, 9900, etc.). As a result of its CMOS technology and low clock speeds (8 MHz max. for the Harris HM-6100A), it had relatively low power consumption (less than 100 mW at 10V/2 MHz) and could be operated from a single supply over the wide range of 4-11V. Thus, it could be used in high reliability embedded systems without the need for any significant thermal management, if the rest of the system was also CMOS.

The 6100 family was used in a number of products, including the DECmate line, DEC's first attempt to produce a personal computer.

The 6100 was available to military specification and since it was dual sourced by Intersil and Harris, it was used in some military products as a low power alternative to the 8080, 6800 etc. Although it had a very simple instruction set and architecture, it was eminently suitable for use in systems that had previously used discrete logic circuits and even relay based controllers.

Intersil sold the integrated circuits commercially through 1982 as the IM6100 family. It was not priced competitively, and the offering failed. The IBM PCs in 1981 cemented the doom of the CMOS-8s by making a legitimate, well-supported small microprocessor computer.

Although this family of ICs had less logic than many competitors, and could have had smaller silicon and therefore undersold competitors, it used CMOS, then a larger technology, and failed.

Contents

  • Description 1
  • Versions and supporting hardware 2
  • References 3
  • External links 4

Description

The 6100 had a 12 bit CPU and closely emulated the PDP-8 (See PDP-8 for a more complete discussion). It had three primary registers: PC (program counter), 12-bit AC (accumulator), and MQ. All two-operand instructions read the AC and MQ and wrote back to the AC. There was no stack pointer; subroutines returned to their callers by jumping back into the main code, typically by storing the return address in the first word of the subroutine itself.

Conditionals in the 6100 only allowed the next instruction to be skipped. Branches were constructed with a conditional and a following jump. There was only one maskable interrupt. When the interrupt was tripped, the CPU stored the current PC in 0000, and then jumped to the location stored in 0001. The interrupt could be disabled or enabled using the IOF and ION (or SKON) instructions.

The 6100 had a 12-bit data/address bus, limiting RAM to only 4K words (6 kB). Memory references were 7-bit, offset either from address 0, or from the PC page base address (obtained by setting the seven least significant bits of PC to zero). Memory could be expanded using the optional 6102 support chip, which added three address lines and thus expanded memory to 32K words (48 kB) in the same way that the PDP-8/E expanded the PDP-8. The 6102 had two internal registers, IFR (instruction frame) and DFR (data), that offset the 4K page when the CPU accessed memory.

Versions and supporting hardware

Intersil offered a variety of related chips[3] to support 6100 systems. The IM6100 CPU was a straight-8 (basic PDP-8 without memory mapping hardware). The IM6101 PIE (Programmable Interface Element) was a basic PDP-8 I/O port. The IM6102 MEDIC (Memory Extension, DMA Controller, Interval Timer) converted an IM6100 into something resembling a PDP-8/E's CPU. The IM6103 PIO (Parallel Input-Output Port), and the IM6402 or IM6403 UART were basic PDP-8 I/O devices on ICs.

Intersil also offered compatible sizes of RAM and ROM: the IM6551 and IM6561 (1 KBit, 256x4) SRAM, the IM6512 (768 Bit, 64x12) SRAM, and the IM6312 (12 KBit, 1024x12) mask programmable PROM.

A selection of these components were offered as the Intersil 6801 CMOS Family Sampler Kit with the 6960 – Sampler PC Board, a single-board system including the IM6100 CPU, IM6101 PIE, the IM6312 ODT (Octal Debugging Technique) Monitor ROM, three 256x4 CMOS RAMs and a UART IM6403.

The basic 6100 was later upgraded to the 6120, which had the 6102 memory controller built-in.

References

  1. ^ "Microprocessors — The Explosion 1975-1976". AntiqueTech.com. 2009-04-21. Retrieved 2010-12-27. 
  2. ^ a b Bell, Gordon (1980), Family Tree of Digital's Computers, (Poster), Digital Equipment Corporation, retrieved 2010-12-27 
  3. ^ Intersil, Data Book 1981, pages 8-77 to 8-211.

External links

  • "Intersil 6100 microprocessor architecture", CPU World
  • Intersil, "IM6100 CMOS Family Sampler"
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.