- Email: [email protected]
conference proceedings
on an error condition, within a clock cycle say, to inspect a processor's register contents. ATLAS, a CP/M computer that accepts plug-in test and measurement modules, overcomes this with a custom high-speed ECL bus designed for the high-speed test environment. This parallel communications scheme works in an asynchronous fashion and supports transfers at rates up to 100 MHz. Starting deliveries around now, the system sports room for two plug-in modules on the basic instrument, plus a rack-mounting option that allows extension.
ADD-ON CONVERTS PERSONAL MICROCOMPUTERS Using the same general-purposecomputer-plus-add-on principle, but with a different kind of price~performance ratio, WES illustrated the use of add-ons that transform cheap mass market personal computers into lab instruments. Its LA 24/1 box, in conjunction with a Pet or Apple microcomputer, provides 24 channels of 10 MHz timing or state logic analysis capability, enough for simple 8-bit microprocessor system debugging, for just 2650 DM. Two extra 250 DM software options can add a trace print facility and reference memory comparison; previous traces or data segments stored on a floppy disc can be compared with current data. Emulation has emerged as a field service tool too, aiding componentlevel diagnosis on boards that would otherwise be swapped, adding to a spiralling float of parts in the spares pipeline. Siemens' SPS-P portable tester caters for systems based on 8080, 8085 or 8086 processors. Accessing the board under test through the system bus edge connector, or directly clipped over the system CPU, the equipment performs a 2-stage test. With the microprocessor disabled, the device tests the contacts of the PCB, control signals, data and address lines, I/O and memories. Direct bitfor-bit comparison is used for PROM testing, to a maximum capacity of 64k-bytes. Then, the processor itself
vol 7 no 5 june 1983
Figure 3. Plug-ms configure Dolch's ATLAS into a range of test instrumentation including emulators and logic analysis - an ECL control bus overcomes speed problems inherent with IEEE-488 systems comes in for a realtime test including interrupt and restart functions. Programs are developed in the assembler language of the device under test. Solartron offer emulation as just one of a number of digital tests available on its Locator field logic tester. Microprocessor-specific pods, currently available for most major 8-bitters and the 8086, first perform a number of pre-programmed tests on the microprocessor, then allow target-specific testing via programs that are developed by the user and carried in PROM sockets. Perhaps the instrument's primary function, however, is its signature analysis capability, and users can now take advantage of a software package running on the Commodore Pet microcomputer to automate the signature collection, documentation and test process. Called ASSIST, the database package documents the signature collection process and produces a printed test sequence for incorporation into product manuals.
FIELD TESTER COPES WITH VLSI Italy's major ATE house, Olivetti Tecnost, approach field testing from a different viewpoint: since the typical field fault is a component failure, the tester uses the in-circuit
principle, but like the emulation approach, retains ease of interfacing by using clip-over DIL probes and power supply hooks and working through the board in a logical sequence testing logic devices by truth-table testing. The current 24-pin MIT-3, suited primarily to MSl-level, is about to be joined by the MIT-4, a combination analogue/digital tester catering for VLSI devices by virtue of up to 64 channels, and faster data rate, to 4 MHz maximum. A logical probing sequence for each board is worked out in advance, with test patterns for each device taken from a library or developed and stored in sequence on a floppy disc, utilizing one of OIEetti's Z8000-based microcomputers configured as a programming station. The test technician, using clip-on DIL probes, works through the circuit under direction of the unit's 40-character display and buzzer until the faulty component is found. A 64-pin LED display indicates the failing pin(s). Test patterns may be applied to the DUT at data-rates up to 4 MHz, provided by the MIT-4's bit-slice processor. Instructions at the programmer's disposal include loop, conditional/unconditional jumps, jump to subroutine, for-next, stop on condition. The basic unit comes with 48 bi-directional channels (expandable to 64) each with 1 k x 4-bit memory. The maximum forcing current is 600 mA, the unit can perform signature analysis on every pin, and four 50V analog channels (two drivers, two sensors) can be added. A programmable switching power supply is available for use in testing.
CONFERENCE PROCEEDINGS The event also staged a conference; divided into five sessions, the papers cover test system principles and structure, maintenance testing, a selection of key presentations from the Cherry Hill conference, software, production testing, testability, component testing and non-electronic product testing. Reprints (five volumes, approx 90 pp each, mostly in German) are available at a cost of £100. Barrie Nicholson, EDN
233
ADD-ON CONVERTS PERSONAL MICROCOMPUTERS Using the same general-purposecomputer-plus-add-on principle, but with a different kind of price~performance ratio, WES illustrated the use of add-ons that transform cheap mass market personal computers into lab instruments. Its LA 24/1 box, in conjunction with a Pet or Apple microcomputer, provides 24 channels of 10 MHz timing or state logic analysis capability, enough for simple 8-bit microprocessor system debugging, for just 2650 DM. Two extra 250 DM software options can add a trace print facility and reference memory comparison; previous traces or data segments stored on a floppy disc can be compared with current data. Emulation has emerged as a field service tool too, aiding componentlevel diagnosis on boards that would otherwise be swapped, adding to a spiralling float of parts in the spares pipeline. Siemens' SPS-P portable tester caters for systems based on 8080, 8085 or 8086 processors. Accessing the board under test through the system bus edge connector, or directly clipped over the system CPU, the equipment performs a 2-stage test. With the microprocessor disabled, the device tests the contacts of the PCB, control signals, data and address lines, I/O and memories. Direct bitfor-bit comparison is used for PROM testing, to a maximum capacity of 64k-bytes. Then, the processor itself
vol 7 no 5 june 1983
Figure 3. Plug-ms configure Dolch's ATLAS into a range of test instrumentation including emulators and logic analysis - an ECL control bus overcomes speed problems inherent with IEEE-488 systems comes in for a realtime test including interrupt and restart functions. Programs are developed in the assembler language of the device under test. Solartron offer emulation as just one of a number of digital tests available on its Locator field logic tester. Microprocessor-specific pods, currently available for most major 8-bitters and the 8086, first perform a number of pre-programmed tests on the microprocessor, then allow target-specific testing via programs that are developed by the user and carried in PROM sockets. Perhaps the instrument's primary function, however, is its signature analysis capability, and users can now take advantage of a software package running on the Commodore Pet microcomputer to automate the signature collection, documentation and test process. Called ASSIST, the database package documents the signature collection process and produces a printed test sequence for incorporation into product manuals.
FIELD TESTER COPES WITH VLSI Italy's major ATE house, Olivetti Tecnost, approach field testing from a different viewpoint: since the typical field fault is a component failure, the tester uses the in-circuit
principle, but like the emulation approach, retains ease of interfacing by using clip-over DIL probes and power supply hooks and working through the board in a logical sequence testing logic devices by truth-table testing. The current 24-pin MIT-3, suited primarily to MSl-level, is about to be joined by the MIT-4, a combination analogue/digital tester catering for VLSI devices by virtue of up to 64 channels, and faster data rate, to 4 MHz maximum. A logical probing sequence for each board is worked out in advance, with test patterns for each device taken from a library or developed and stored in sequence on a floppy disc, utilizing one of OIEetti's Z8000-based microcomputers configured as a programming station. The test technician, using clip-on DIL probes, works through the circuit under direction of the unit's 40-character display and buzzer until the faulty component is found. A 64-pin LED display indicates the failing pin(s). Test patterns may be applied to the DUT at data-rates up to 4 MHz, provided by the MIT-4's bit-slice processor. Instructions at the programmer's disposal include loop, conditional/unconditional jumps, jump to subroutine, for-next, stop on condition. The basic unit comes with 48 bi-directional channels (expandable to 64) each with 1 k x 4-bit memory. The maximum forcing current is 600 mA, the unit can perform signature analysis on every pin, and four 50V analog channels (two drivers, two sensors) can be added. A programmable switching power supply is available for use in testing.
CONFERENCE PROCEEDINGS The event also staged a conference; divided into five sessions, the papers cover test system principles and structure, maintenance testing, a selection of key presentations from the Cherry Hill conference, software, production testing, testability, component testing and non-electronic product testing. Reprints (five volumes, approx 90 pp each, mostly in German) are available at a cost of £100. Barrie Nicholson, EDN
233