What a great project!
The RAM pattern test used by Fluke might be of interest here. It will
identify stuck address bits - but I have no idea of exactly the process
used to generate the Fluke RAM test. Perhaps someone else here might have
some algorithms that they can recommend?
I was just testing an Asteroids today and the 9010 showed a DCD error (was
a failing A10 on the Vector RAM) - which proved to be a problem with a
replacement socket. RAM tests must be able to check that address lines are
all working as well as the data can be read out...so offset the pattern by
one bit for each address line to make sure you pick up these errors!
There are other errors that RAM can have, but this is a start, and I've
been looking for a Static RAM free standing device for a while
now...something like the Star Tek Dynamic tester (schematics and manual
just uploaded to the FTP archive) would be great - just drop in your RAM
and dial up the speed until it fails...
John :-#)#
At 06:32 PM 29/12/2003, pc2jamma wrote:
>Hello Folks !
>
>The first part of the project, will make a Test Pattern, once the RS232
>does not have enough speed to make a the Speed Test. Most of SRAM memories
>fail at this point...
>
>It consists on fill all addresses with 0s, 1s and pattern like
>
>0000000000
>0000000001
>0000000010
>0000000100
>0000001000
>0000010000
>0000100000
>0001000000
>0010000000
>0100000000
>1000000000
>0100000000
>0010000000
>0001000000
>0000100000
>0000010000
>0000001000
>0000000100
>0000000010
>0000000001
>
>And repeat at inverse way (0s in place os 1s and 1s in place of 0s)
>
>The second part of the project, I'm planning to make on clock circuit (up
>to 20MHz) to make the Speed Test, filling all addresses with 0s and
>another test filling with 1s.
>
>The software control, will be another important part of this project.
>
>I hope to share experiences with you guys, and ALL comments will be very
>welcome !!!
>
>I'm studing PIC microcontroles, and soon I hope to have one PCless tester :)
>
>
>Thank you
>
>José Luiz Martins
>
>
>....
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Received on Mon Dec 29 21:57:19 2003
This archive was generated by hypermail 2.1.8 : Mon Dec 29 2003 - 22:50:01 EST