How the comparing algorithm works? It works like this :
After an IC library file has loaded (or created), every inputs send to the IC pin socket, while the outputs are keep high. After the stable condition arised, the IC output under test will change byt itself, in accordance by the device itself (the kind of gate). And then the logic of IC pin socket read back again, and the outputs are compared to the boolean thruth table from IC library file (so the IC library must exactly meet the data book thruth table).
Original editor still have many bugs, I have improved the editor layout (10.603 Bytes) and keys, so it is convenience to use.
If the IC has clock, then the clocks are sending pulse (1 high and 1 low) depends on the clock is a rising edge signal or a falling edge signal (+Clock or -Clock). and then the outputs are read back and compared to the IC librarary file. If the logic outputs are the same as the data, so the IC device passed, on the other way the device failed. That's all.
HARDWARE TESTING
Because this project needs more attention when assembly, I already made a program to test it after you have finished (hw_test.exe). Here you must prepare a voltage tester or if it could be a logic probe. I used a self made logic probe and it seems a good one from ETI-Project (If I have time, I will write it later). After everything is okay, test the circuit by applying the voltage to it. Watch out something goes wrong. If nothing happened and the circuit seems work normally, connect it to LPT port. Run the software for testing the hardware. The menu (7.590 Bytes) are for testing the PPI-8255, logic write to pins socket, logic read from pins socket, IC pin power selectable, and overall connection (7.233 Bytes). Run from the first to the last one by one. Every step you will be prompted to check the proper pin hardware connection. If the result not the same, stop the process and examine carefully where the step stopped at. After you fixed it, run again from the beginning. Good luck!!!NEW IC DEVICE FILE FORMAT
IC library file format still the same from the original, but I added some for IC compatibility type and IC description and copyright for appreciate of his works. The extension is also *.CHP. Both software still can used the file format each other. ChipTest.exe can used new format and ignore the feature parts, but if edited with it will lost the feature. IcTester.exe can still used old format but without the feature parts, if edited with it will added the feature. The complete file format are like below:*** CHIP TESTER DEVICE FILE
#
#
*** PIN COUNT
Constant_PC_1 ;IC pin Q'ty
Constant_PC_2 ;Input pin Q'ty
Constant_PC_3 ;Output pin Q'ty
Constant_PC_4 ;Clock(+) pin Q'ty
Constant_PC_5 ;Clock(-) pin Q'ty
Constant_PC_6 ;Edited pin Q'ty
*** PIN TYPES
Constant_PT_1 ;Pin 1
Constant_PT_2 ;Pin 2
. ;Pin 3 through IC pin Q'ty
. ;Pin types are : 1 = input, 2 = Output,
. ;3 = Clock(+), 4 = Clock(-),
. ;5 = Vcc, 6 = Gnd, 7 = Unused
Constant_PT_(Constant_PC_1) ;Last IC pin
*** TEST DATA
Constant_TD_0 ;Step check (Max. 255 step)
Constant_TD_11 Constant_TD_12 ... Constant_TD_1(Constant_PC_6) ;Matrix for Boolean Truth Table
Constant_TD_21 Constant_TD_22 ... Constant_TD_2(Constant_PC_6)
.
.
.
Constant_TD_(Constant_TD_0)1 Constant_TD_(Constant_TD_0)2 Constant_TD_(Constant_TD_0)(Constant_PC_6)
*** END ;Compatibility for Paul Stenning IC Data File Format
*** IC COMPATIBLE TYPES
String_CT_1 ;Reserved for 7 name
String_CT_2 ;Max. 8 characters
.
.
.
String_CT_7
*** DESCRIPTION
String_D ;Max. 60 characters
*** COPYRIGHT
Originated by: Paul Stenning (1993)
Modified by: David Setya Atmaja (1999)
Sample of this file format for old version type 7400 IC TTL and new version like this. As mention from his page, all digital type IC can be checked accept that those incorporating analog techniques, such as monostables and phase locked loops. Both TTL's or CMOS's types were accepted. All IC's that have its boolean thruth table can be implemented here. You can create your own library database (because mine was not complete yet) by inputed this boolean thruth table from data books and experiment with it. This is what we call, "Hope you having fun with electronics !!!!!".Now you can download my second version of libraries database (72.996 Bytes)
PART LISTS
The components for building this paralel version of IC-Tester are : 1. Resistors :
R1 ~ R24 = 220 Ohm ...................................................... 24 pcs
R25 ~ R49 = 4k7 ......................................................... 25 pcs
2. Capasitors :
C1 ~ C3 = 100 nF (for IC decoupling, used as necessary ) ................ 3 pcs
C4 = 470 uF/16V (for power input) ....................................... 1 pcs
3. Semiconductors :
IC1 = PPI-8255A-5 or equivalent type (Parallel Peripheral Interface) ... 1 pcs
IC2 = 74LS138 (3 to 8 channel decoder) .................................. 1 pcs
IC3 ~ IC5 = 74LS374 (Octal latch) ....................................... 3 pcs
IC6 ~ IC9, IC14 = 74LS07 (Hex buffer) ................................... 5 pcs
IC10 ~ IC12 = 74LS244 (Octal tri-state bus driver) ...................... 3 pcs
IC13 = 74LS04(Hex Inverter) ............................
i think this content is more benefit to the visitors , please comment your Queries about this post. "Thank You"
ReplyDeletegreetings
ReplyDeleteThe diagram of the pcb has a major flaw, 5v only goes to the relays not to the main part of the board.
A track or link has been left out.
H J Quinn
hjquinn@bigpond.net.au
Dear sir, you have done excellent work. I have made the Paul Stenning edition (serial interface) but the device does not work. Some of the pins of the ZIF socket are working properly but the whole device is faulty, when cheking for instance the 7414. So every device I try to check the result is "failed". Please, is it possible to give me some advice - the faulty device is due to hardware or software. My email is: kouzakiotis@yahoo.gr
ReplyDeleteThank you very much in advance
Lefteris Kouzakiotis