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Local Area Networks: Part 1 - Technology
classes of program which may need to run isochronously. Typical applications, say the authors, requiring isochronous programs (in which loops Bautista, A, Tirado, J F., Ruz, J J and take an exact length of time) are sampHermida, R 'An architectural design for simultaneous ling and data acquisition for signal processing, digital time-keeping and timemicrodiagnostic' Microproc. and Microof-day display, programs for disc transprog. Vol 9 No 1 (January 1982) port controllers, multiprocessor systems pp 27-37 and network systems with isochronous Simultaneous microdiagnostic is the and synchronized programs in transexecution of diagnosis microroutines mitters and receivers. The paper gives by a system while performing its several isochronous programming technormal tasks. This paper deals with niques which include the use of ballast the provision of a monoprocessor statements, which are introduced in proarchitecture with minimal redundangrams to ensure that all routes through cies to enable simultaneous execution a program loop take precisely the same of two microprograms on different number of processor clock cycles as modules in the system. Concurrent the number of cycles in the longest execution of several independent route. The conclusions are that realmicrodiagnostics is proposed so that time programs should only be designed the necessary compatibility between for isochronous loops when the applinormal processing and a sole diagnostic cation demands. Isochronous operation could be shared among several test cannot be guaranteed purely from the alternatives. Microdiagnostic is driven software viewpoint, it continues, the by an auxiliary control unit where underlying hardware system must also there are microaddress and data be free from any hidden asynchronous registers for every test alternative. activity.
Hardware
Edelson, R H 'Dual Systems' 32k CMOS nonvolatile high-speed memory' Interface Age Vol 7 No 3 (March 1982) pp 60-64 CMOS is as.volatile as almost any semiconductor RAM but because they require so little standby power, it is feasible to provide backup power from onboard batteries. The 32k board described in this article requires a maximum of 20 #A during standby allowing it to retain data for a guaranteed three years with lithium batteries on board. Operating current too is low, typically 650 mA for the 32k board. The article concludes that the Dual Systems' series provides a rugged board with 5-10 year storage at a reasonable price ($895 for the 32k board). Fay, D (~ M and Telford, R W 'Hardware difficulties associated with isochronous programs'J. Microcomput. Applic. (1982) Vol 5 No I pp 43-47 Timing of isochronous programs can be upset by asynchronous activity such as with interrupts, DMA, memory refresh and wait states. The paper reviews these problems and lists
vol 6 no 5june 1982
Grierson, I R 'Modern Developments in gate arrays' Electron. and Power Vol 28 No 3 (March 1982) pp 244-248 A gate array is a digital IC in which only the interconnection pattern is special to a specific circuit design. The gate array manufacturer mass produces 'uncommitted' gate array slices with the transistors etc formed but lacking the final metallization pattern needed for interconnection. Slices are committed by applying a metallization pattern, dicing and packaging. Such technology promises cost reductions for customized circuits. This article does not consider the technical fundamentals but rather considers the reasons for the recent boom in gate arrays and their present and future developments. The article claims that ECL and CMOS technologies will dominate the highand low-speed applications while one or two of the other (probably CDI and one of the TTL variants) will occupy the middle ground. The implementation of CAD to gate arrays will be a key factor as to which manufacturers prosper and which fall by the wayside.
Joshi, S, Mithani, D and Stephonsen, S 'A bipolar microprogrammable processor' Electron. Prod. Des. Vol 3 No 2 (February 1982) pp 34-38 Advanced Micro Devices has combined its proprietary IMOX II process technology with the VLSI bipolar circuit design technology of scaled ECL to produce the Am29116 16-bit bipolar microprocessor. This article describes this device said to be the largest and most complex bipolar chip produced. Although the device uses ECL circuitry, it is TTL compatible at the inputs and outputs and runs from a standard 5V plus ground power supply. Kotelly, G 'Local Area Networks: Part 1 Technology' EDN Vol 27 No 4 (17 February 1982) pp 109-122 Kotelly, G 'Local Area Networks: Part 2 Low and Midrange Products' EDN Vol 27 No 4 (17 February 1982) pp 127-138 Kotelly, G 'Local Area Networks: Part 3 High Performance Products' EDN Vol 27 No 4 (17 February 1982) pp 143-150 Regular readers of Microprocessors and Microsystems know that there is no shortage of reports and surveys that predict very rapid growth in the use of local area network technology. EDN have produced a special report on LANs that takes the reader from the definition of a LAN through to voice and video transmission over shielded broadband coax, and has contributions from several specialists. According to Ralph Ungermann of Ungermann-Bass Inc. the local area network market is 'immature and confusing'. The initial emphasis in the first article is placed on the identification of key issues for discussion. These include which interfaces and software protocols are supported by the system (such as an RS232C and IBM 2780 Bisync), what communication and system features (such as directory and virtual service) come with the attached device and what network administrative tools allow easy configuration, maintenance and monitoring of the network.
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Hardware
Edelson, R H 'Dual Systems' 32k CMOS nonvolatile high-speed memory' Interface Age Vol 7 No 3 (March 1982) pp 60-64 CMOS is as.volatile as almost any semiconductor RAM but because they require so little standby power, it is feasible to provide backup power from onboard batteries. The 32k board described in this article requires a maximum of 20 #A during standby allowing it to retain data for a guaranteed three years with lithium batteries on board. Operating current too is low, typically 650 mA for the 32k board. The article concludes that the Dual Systems' series provides a rugged board with 5-10 year storage at a reasonable price ($895 for the 32k board). Fay, D (~ M and Telford, R W 'Hardware difficulties associated with isochronous programs'J. Microcomput. Applic. (1982) Vol 5 No I pp 43-47 Timing of isochronous programs can be upset by asynchronous activity such as with interrupts, DMA, memory refresh and wait states. The paper reviews these problems and lists
vol 6 no 5june 1982
Grierson, I R 'Modern Developments in gate arrays' Electron. and Power Vol 28 No 3 (March 1982) pp 244-248 A gate array is a digital IC in which only the interconnection pattern is special to a specific circuit design. The gate array manufacturer mass produces 'uncommitted' gate array slices with the transistors etc formed but lacking the final metallization pattern needed for interconnection. Slices are committed by applying a metallization pattern, dicing and packaging. Such technology promises cost reductions for customized circuits. This article does not consider the technical fundamentals but rather considers the reasons for the recent boom in gate arrays and their present and future developments. The article claims that ECL and CMOS technologies will dominate the highand low-speed applications while one or two of the other (probably CDI and one of the TTL variants) will occupy the middle ground. The implementation of CAD to gate arrays will be a key factor as to which manufacturers prosper and which fall by the wayside.
Joshi, S, Mithani, D and Stephonsen, S 'A bipolar microprogrammable processor' Electron. Prod. Des. Vol 3 No 2 (February 1982) pp 34-38 Advanced Micro Devices has combined its proprietary IMOX II process technology with the VLSI bipolar circuit design technology of scaled ECL to produce the Am29116 16-bit bipolar microprocessor. This article describes this device said to be the largest and most complex bipolar chip produced. Although the device uses ECL circuitry, it is TTL compatible at the inputs and outputs and runs from a standard 5V plus ground power supply. Kotelly, G 'Local Area Networks: Part 1 Technology' EDN Vol 27 No 4 (17 February 1982) pp 109-122 Kotelly, G 'Local Area Networks: Part 2 Low and Midrange Products' EDN Vol 27 No 4 (17 February 1982) pp 127-138 Kotelly, G 'Local Area Networks: Part 3 High Performance Products' EDN Vol 27 No 4 (17 February 1982) pp 143-150 Regular readers of Microprocessors and Microsystems know that there is no shortage of reports and surveys that predict very rapid growth in the use of local area network technology. EDN have produced a special report on LANs that takes the reader from the definition of a LAN through to voice and video transmission over shielded broadband coax, and has contributions from several specialists. According to Ralph Ungermann of Ungermann-Bass Inc. the local area network market is 'immature and confusing'. The initial emphasis in the first article is placed on the identification of key issues for discussion. These include which interfaces and software protocols are supported by the system (such as an RS232C and IBM 2780 Bisync), what communication and system features (such as directory and virtual service) come with the attached device and what network administrative tools allow easy configuration, maintenance and monitoring of the network.
251