Verifying software performance with a logic analyser

i Luna, F D and i Belata, A S

Stehlin, R A

uses a ciphering standard implemented on an 8085 microprocessor.

'A hovercraft radio control system' Mundo Electronics No 146 (December 1984) pp 123-130 (in Spanish)

'Bergeron plots predict delays in high-speed TTL circuits' EDN Vo129 No 23 (15 November 1984) pp 293-298

Ryan, T A radio control system for a twinengined hovercraft is described. Speed control of the two engines uses pulse-width modulation techniques and power control is accomplished using power MOSFET devices.

In high-speed circuits (clock rate in the order of 10 MHz) the propagation delay along an interconnect can equal or exceed gate transition times and result in reflections. Some sort of examination of switching behaviour is therefore necessary, but traditional transmission-line equations are difficult to use because neither the input impedance nor the output impedance of a gate is linear. Bergeron plots provide a simpler method as they employ a graphic approach that addresses both transmission-line impedance and the nonlinear characteristics of TTL circuits. Examples are given of the use of Bergeron plots in predicting the results of both 1-to-0 and 0-to-1 transitions.

'Verifying software performance with a logic analyser' New Electron. Vo117 No 24 (11 December 1984) pp 45-50 Despite their sophisticated state analysis capabilities, logic analysers are normally used for troubleshooting only in hardware. Software verification is performed on a comparatively expensive microprocessor development system (MDS) with software and logic analysis features. Ryan writes about the 1630G logic analyser, which is geared towards software verification with features including performance histograms (state overview and time interval) and time tags. The operation and usefulness of these features are discussed.

Ram~rez, I R and Vinyes, I 'A cryptographic control system for buildings access control' Mundo Electronico No 146 (December 1984) pp 99-104 (in Spanish) Ramlrez and Vinyes describe a prototype restricted-area access control system. Users are allowed access via a magnetic card bearing a personalized cipher. The system

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FAMILY More and more systems with a 32°bit architecture are hitting the market. Many are based on the 68000 family of chips. For people contemplating or already using such a system, Microprocessors and Microsystems presents the state of the art in 68000-based computing. Articles cover applications, VMEbus, Xenix and Pick, and MODULA-2, POPLOG and LISP. The issue also includes a complete introduction to the 68020 processor. The collection is essential reading for systems designers, systems engineers and OEMs. For further details please contact: A n n e B r o w n e , Editor, B u t t e r w o r t h S c i e n t i f i c Ltd., PO B o x 6 3 , W e s t b u r ] / H o u s e , Bury S t r s s t , G u i l d f o r d , S u r r e y GUR 5BH, UK. T e l e p h o n e : ( 0 4 8 3 ) 3 1 2 6 1 Telex: 8 5 9 5 5 6 SCITEC G

vol 9 no 2 march 7985

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