CN2043763U

CN2043763U - Microcomputerized measuring apparatus for digital integrated circuit features

Info

Publication number: CN2043763U
Application number: CN 87211391
Authority: CN
Inventors: 刘必虎; 吴迎潮
Original assignee: East China Normal University
Current assignee: East China Normal University
Priority date: 1987-11-16
Filing date: 1987-11-16
Publication date: 1989-08-30

Abstract

The utility model relates to a microcomputerized measuring apparatus for digital integrated circuit functions, and aims to use the microprocessor circuit technique to measure the function of a digital integrated circuit device. The measuring apparatus can measure the functions of the TTL from 14 pins to 24 pins and a CMOS digital integrated circuit. The model of a measured digital integrated circuit is inputted by a keyboard, a measuring key is pressed, the measurement can be automatically carried out, and an LED indicator displays the result. The measuring apparatus is fixedly provided with the EPROM27128 of more than 300 measuring programs, remains the storage quantity with 7K, can program the measuring program of the digital integrated circuit of a new product, and thus also has the potential of the extended function. The utility model has the characteristics of rapidity, accuracy and low cost, and is an ideal measuring apparatus for the digital integrated circuit.

Description

Microcomputerized measuring apparatus for digital integrated circuit features

The utility model relates to a kind of microcomputer testing tool that can test the function of the TTL of 14～24 pin of various models commonly used and cmos digital integrated circuit, belongs to electronic technology field.

For miscellaneous digital integrated circuit is tested, measuring technology commonly used is each digital integrated circuit to be adopted the test circuit of a special use.It is the test circuit complexity not only, and effort is time-consuming during test, but also is easy to cause the damage of measured number integrated circuit.

For example, day disclosure special permission communique (A), the digital IC tester that clear 59-139640 is contained mainly is made up of microprocessor, storer etc., wherein store memory has test procedure, by the quality of digital integrated circuit chip before the probe test inclosure shell.Earlier chip is carried out pointwise test, then test result is sent into microprocessor, compare with there being the data in the storer in advance, at last comparative result, i.e. the quality of chip input controller, or show, or make control corresponding.

And for example, the IST-370 type integrated circuit tester of the U.S. mainly also is made up of microprocessor and storer, but because it is in being also included within test of amplifier integrated circuit, so it has the test circuit complexity, costs an arm and a leg and the shortcoming of maintenance difficult.In addition, it can only be tested the following digital integrated circuit of 20 and 20 pin in addition and be difficult to expand the weak point of testing kind.

The digital IC tester of latest domestic is not also used microprocessor technology, and they are often dressed up with more digital integrated circuit, so test circuit is very complicated, costs an arm and a leg.

The purpose of this utility model is with microprocessor (Z80-CPU), Erasable Programmable Read Only Memory EPROM (EPROM27128) and their circuit and two test jack (20 and 24 pin) composition testers of inserting usefulness for the measured number integrated circuit, realize once measuring simultaneously the quality of 24 pin and following tested TTL of 24 pin or cmos digital integrated circuit repertoire, not only save time but also laborsaving; Employing is solidified with for required large buffer memory (16K) Erasable Programmable Read Only Memory EPROM EPROM27128 test procedure, cheap of test kind more than 300 digital integrated circuit commonly used, guarantees that the utility model almost can test any digital integrated circuit device; Also have the 7K memory margin among the EPROM27128, can be used to write the test procedure of fresh product digital integrated circuit, make the utility model not only be easy to the extend testing kind, and the expansion potentiality are big.

Description of drawings:

Fig. 1 is a system chart of the present utility model;

Fig. 2 (a) and (b) and (c) be wiring diagram of the present utility model;

Fig. 3 is a system software process flow diagram of the present utility model;

Fig. 4 used wiring diagram that is the utility model when test 74LS00 device;

Fig. 5 used wiring diagram that is the utility model when test CC40194 device;

Fig. 6 used logic function table that is the utility model when test 74LS00 device;

Fig. 7 used logic function table that is the utility model when test CC40194 device;

Fig. 8 is the allocation of space situation of EPROM and RAM in the utility model;

Fig. 9 is the address assignment situation of two PIO interface in the utility model;

Figure 10 is an outside drawing of the present utility model.

Among the figure, 1 is 24 pin test jacks, and 2 is 20 pin test jacks, the 3rd, Z80-PIO1 interface, the 4th, Z80-PIO2 interface, the 5th, 10K Ω resistance, the 6th, LED seven-segment display, the 7th, keyboard, the 8th, RAM2114 read-write memory, the 9th, EPROM27128 Erasable Programmable Read Only Memory EPROM, the 10th, memory decoder, the 11st, reset circuit, the 12nd, Z80-CPU microprocessor, the 13rd, clock signal oscillator, the 14th, I/O interface code translator, the 15th, relay, the 16th, 5G1413 driver.

As can be seen from Figure 1, the utility model mainly contain Z80-CPU microprocessor 12, Z80-PIO1 and-

PIO2 interface

3 and 4, I/O interface code translator 14, EPROM27128 Erasable Programmable Read Only Memory EPROM 9, RAM2114 read-write memory 8, LED seven-

segment display

6,24 and 20

pin test jacks

1 and 2 and part such as keyboard 7.Keyboard 7 has 12 keys: 10 numeric keys (0～9), a reset key and a feeler switch.Bus system (address bus AB, data bus DB and clock signal bus CB) and some other wiring connect together each part mentioned above, form the dedicated microcomputer that to carry out a cover complicated process, the dedicated microcomputer that in fact the utility model comes to this.A whole set of program comprises that the test procedure of watchdog routine, master routine, subroutine and more than 300 kind of digital integrated circuit deposits and be solidificated among the Erasable Programmable Read Only Memory EPROM 9, carries out same set of program to guarantee that the utility model is each.For keeping drawing clean and tidy, Fig. 1 does not mark the power supply that almost need be connected with each part.

Fig. 2 (a) and (b) and (c) show wiring diagram of the present utility model.Should be stitched together them when seeing.Can find out the full details that connects between the utility model each several part from wiring diagram.During dress system the utility model, can be divided into three to whole circuit by the diagram dotted line: I, II and III.I and II are printed-wiring board (PWB).Connection on the plate between the components and parts, identical with wiring diagram.The panel components and parts: 24 and 20

pin test jacks

1 and 2, LED seven-segment display 6, red LED indicator, green LED indicator and keyboard 7 all must be installed in the same one side of II plate, make when the II plate is packed casing into, above-mentioned components and parts just in time can pass from the hole of panel, referring to Figure 10.No panel components and parts on the I plate, when the I plate was packed casing into, the position can be particular about.Connect with polycore cable between I and the II, III is a power transformer, and is heavy than benzene, preferably is installed in the bottom of casing.Power switch K can be installed in the back side or the side of casing.Be connected with two wiring between II and the III.

Content of the present utility model and principle of work in conjunction with Fig. 1, Fig. 2 (a) and (b), (c) and Fig. 3, are described as follows.

Z80-CPU microprocessor 12 and EPROM27128 Erasable Programmable Read Only Memory EPROM 9 are most important two parts.There is a complete set of program of forming by rule instruction among the latter.The former carries out the program that exists among the latter in the mode of an instruction.After the former obtained an instruction, just the connotation of analysis instruction ordered suitable part to go to finish the task of instruction regulation again.Article one, after instruction is finished, take off an instruction again ... for all parts are worked harmoniously, promptly carry out specific task in the specific moment, adopt time clock as time reference for this reason.13 is the clock signal oscillator among Fig. 2 (a), and oscillation frequency is that 3.9936MHz, oscillator signal are through U ₃₀Behind two divided-frequency, requisite time clock when can be used as the entire circuit co-ordination.

(1) starts shooting with K switch.The utility model can be finished initialize routine automatically, LED seven-segment display 6(first left) can show proposition symbol " P ", but expression the utility model has been in the state of operate as normal.

(2) key in the model (numerical portion) of intending surveying digital integrated circuit with keyboard 7, LED seven-segment display 6 can show this model.Now

insert test jack

1 or 2 intending surveying device.As device is below 24 pin, inserts the test jack 2(limit that keeps left and lays); As device is 24 pin, inserts test jack 1.

(3) click feeler switch, the utility model just changes the test procedure that measured device is tested over to.

(4)～(6) the input model with have in the EPROM27128 EPROM (Erasable Programmable Read Only Memory) 9 first kind ... the i kind ... compare one by one with the model of last a kind of digital integrated circuit, only have two kinds of situations:

(7) do not wait (denying) all the time as both, Z80-CPU microprocessor 12 is with executive routine (7) so, LED seven-segment display 6 shows "----" symbol, do not have the data of measured device in the expression EPROM27128 Erasable Programmable Read Only Memory EPROM 9, this device belongs to the row that can not test.

(8)～(11) when comparing, certain equates just in time that as both Z80-CPU microprocessor 12 changes executive routine (8) immediately into so.(8) and (9) be the test procedure of measured device.After 12 pairs of these programs of Z80-CPU microprocessor are analyzed, order Z80-PIO1 or-

PIO2 interface

3 or 4 carries the voltage of this procedure stipulation to each utmost point of measured device (test jack pin).Fig. 2 (c) shows the wiring diagram that

test jack

1,2 is connected with Z80-PIO1, Z80-PIO2 interface 3,4.The electric current that flows through measured device during test is bigger, and Z80-PIO1, Z80-

PIO2 interface

3,4 can not supply big like this electric current, so the V of measured device _CCMust directly be connected to 5V power supply and ground wire with the GND pin.For when testing different digital integrated circuits, the pin of

test jack

1,2 can directly be linked to each other with ground wire with power supply respectively as required, can be by the break-make between relay 15 control pins and power supply or the ground wire.Whether relay 15 works, and can be controlled by Z80-PIO2 interface 4, drives relay 15 reliably by 5G1413 driver 16.When Z80-PIO2 interface 4 output low levels, relay 15 is failure to actuate.Wherein 10K Ω resistance 5 is as the collector load resistor of OC door, and it has been the effect that high level is risen to 5V to input, the not influence of output of general integrated circuit.When measured device was free pin, the 5V power supply can be used as the high level input of Z80-PIO1, Z80-

PIO2 interface

3,4 by 10K Ω resistance 5.In seven relays 15, J ₆Play the power supply master switch.If J ₆Disconnect, no matter then whether other relays move,

test jack

1,2 will disconnect with power supply and ground wire.J ₀～J ₅Play branch switch.Work as J ₆During adhesive, the 5V power supply just is connected to the pin of

test jack

1,2 by 10K Ω resistance 5, at this moment J ₀～J ₅Can be used to provides 5V power supply and ground wire to different pins.So far measured device has been connected among the test circuit of special this device of test, next Z80-CPU microprocessor 12 executive routines (9) the logic level of each pin of measured device (1 or 0) with have that measured device standard logic level compares in the EPROM27128 Erasable Programmable Read Only Memory EPROM 9, may be following two kinds of situations only:

(10) both equate (being), and green LED indicator is bright; The function of expression measured device is normal;

(11) both do not wait (denying), and red LED indicator is bright, and the function of expression measured device is undesired.

No matter green LED is luminous, and still red LED is luminous, and program will turn back to the inlet of program (3).Need test if any a large amount of same model devices, only need change them one by one, when whenever changing a slice, click feeler switch, can test, needn't be by reset key and key in the device model again.Test the device of another model as need,, click reset key, then key in the model of measured device, press feeler switch again and get final product as long as insert measured device.

When Figure 4 and 5 have shown the utility model test 74LS00 and CC40194 device respectively, the wiring diagram between test jack 2 and the Z80-PIO1 interface 3.Corresponding tested 74LS00 or the power lead of CC40194 device and the input end that ground wire can be regarded as Z80-PIO1 interface 3, selecting the corresponding position of word is " 1 "; Each sky pin of measured device is connected to 5V by 10K Ω resistance 5, and as the input of Z80-PIO1 interface 3, selecting the corresponding position of word is " 1 "; The measured device output pin is as the output of Z80-PIO1 interface 3, and selecting the corresponding position of word is " 0 ".

Fig. 6 and 7 shows the logic function table of digital integrated circuit 74LS00 and CC40194 respectively.The quality of a device function of test, be that input end at this device adds logic level " 0 " or " 1 ", measure its output logic level then, the logic level of the menu regulation that records result and this device is compared, as inconsistent, judge that this device is bad; As unanimity, judge that then this device is good.According to mentioned above principle, logic function table according to concrete digital integrated circuit, must compile out the logic function test procedure of this device, for the memory capacity of saving Erasable Programmable Read Only Memory EPROM be convenient to making software, should call for each test procedure with nonexpondable shared routine as subroutine.Main subroutine has OUTAB, D100M3, COMP, COMPF and J ₀, J ₁, J ₂, J ₃, J ₄, J ₅Deng.

Fig. 8 has shown the allocation of space situation of EPROM and RAM in the utility model.Work as Y ₀When=PROMSEL is selected, EPROM27128 Erasable Programmable Read Only Memory EPROM 9 is just selected, its corresponding address space is 0000H～3FFFH, be solidified with the test procedure of more than 300 kind of digital integrated circuit in the EPROM27128 Erasable Programmable Read Only Memory EPROM 9, still had the surplus of 7K available.If the digital integrated circuit of fresh product is arranged, as long as write out the test procedure of this device logic function, and it is deposited in the Erasable Programmable Read Only Memory EPROM 9, just the utility model can be tested this device.This explanation the utility model is also having sizable potentiality aspect the expansion test specification.

Also be solidified with following main subroutine in the EPROM27128 Erasable Programmable Read Only Memory EPROM 9 that the utility model adopts:

Address label title and effect

01C9H BADB test result subroutine; Red light is bright, and the indication measured device damages.

01E3H G00D test result subroutine; Green light is bright, and the indication measured device is intact.

0262H D100MS delay subroutine; Postpone 100ms.

026CH J ₀The relay subroutine; J ₆, J ₀Adhesive.

0274H J ₁The relay subroutine; J ₆, J ₁Adhesive.

027CH J ₂The relay subroutine; J ₆, J ₂Adhesive.

0284H J ₃The relay subroutine; J ₆, J ₃Adhesive.

028CH J ₄The relay subroutine; J ₆, J ₄Adhesive.

0294H J ₅The relay subroutine; J ₆, J ₅Adhesive.

029CH OUTAB0 power supply subroutine; 16 pin measured devices add power supply.

02A3H OUTAB1 power supply subroutine; Special measured device adds power supply.

02AAH OUTAB2 power supply subroutine; Special measured device adds power supply.

02B1H OUTABS power supply subroutine; Special measured device adds power supply.

02B8H OUTAB4 power supply subroutine; 14 pin measured devices add power supply.

02BFH OUTABF5 power supply subroutine; 20 pin measured devices add power supply.

10D0H OUTABFO power supply subroutine; 24 pin measured devices add power supply.

0218H COMP test subroutine;

Survey

14,16 pin measured devices.

023DH COMPF test subroutine; Survey 20,24 pin measured devices.

The utility model is compared with the existing digit integrated circuit tester, although both used microprocessor and memory, can only point-to-point measurement in view of the latter, and the former but can measure simultaneously to all pins of measured number integrated circuit; The latter can only test 20 pin and the following digital integrated electronic circuit of 20 pin, and the former but can test 24 pin and the following digital integrated electronic circuit of 24 pin; Latter's test circuit complexity, expensive, maintenance difficult, the former test circuit is simple, low price, maintenance is easily; The latter is difficult to the extend testing kind, the former not only is easy to the extend testing kind, and the expansion potentiality are big, so, the utility model be a kind of cheapness, succinct, be convenient to the tester extend testing kind, that can once accurately and easily measure measured number integrated circuit repertoire quality.

Claims

1, microcomputer digital integrated circuit functional tester is by Z80-CPU microprocessor 12, Z80-PIO interface 3,4, I/O code translator 14, EPROM27128 Erasable Programmable Read Only Memory EPROM 9, RAM2114 read-write memory 8, LED seven-segment display 6, test jack 1,2 is formed, it is characterized in that adopting the circuit connection structure that to test the digital integrated circuit function, wherein be solidified with more than 300 test procedure in the EPROM27128 Erasable Programmable Read Only Memory EPROM 9.

2, tester according to claim 1 is characterized in that the circuit connection structure of EPROM27128 Erasable Programmable Read Only Memory EPROM 9.

3, tester according to claim 1 is characterized in that the circuit connection structure of test jack 1,2 and Z80-PIO interface 3,4.

4, tester according to claim 1 is characterized in that the circuit connection structure of 10K Ω resistance 5 and test jack 2.