I'm having trouble programming my first chip. I'm using a sst 27sf512 and it looks like I can erase the chip, but it never successfully programs, I always get verification errors. I'm using an old parallel chipmax programmer. I'm sure the programmer works, we use it at my work all the time. I've never programmed this type of chip with it before, so I'm wondering if that is the issue? I have two chips and can't get either to program successfully.

Any help would be greatly appreciated!

 

I looked at what I could find about the ChipMax online, and it does not seem to directly support the 27SF512. However, as the 27SF512 was designed as a replacement for older EPROM products I would think you should be able to find a setting for the ChipMax that will program them.

What chip setting are you using in the Chipmax software? You need to find one that matches the voltage specs for the 27SF512: Vpp = 11.4v - 12v, Vdd = 4.5v - 5.5v.

I bet that the reason it seems like it's erasing properly is because the chip is already blank. However, I'm not sure that even if you do get it to program that you would also be able to erase. From what I can tell from skimming the datasheet for one of the supported FLASH chips (28F512), is that those are erased by writing a command to the chip, while the 27SF512 is erased with a simple pulse on the CE# pin. Therefore, the erase modes between the two would be incompatible. And, as far as I can tell the 28/29Fxxx would be the only supported chip series that the ChipMax would offer an erase option for.

I'm not directly experienced with the ChipMax or it's software. All that I know about it I got from the ChipMax link below.

Here's a list of the documents that I have used for reference:

• SST27SF512 Datasheet
• 28F512 Datasheet
• ChipMax Info

 

The sst chip comes up in the prom list on the chipmax software and the algorithm settings have correct voltages. I have read the chips after an erase and after a program and can see that it writes some data correctly and that it can erase the chip correctly. I even went as far as writing a program to create a 4k binary file that has a counter that increments byte by byte so I could compare what was on the chip to what I want it to be. We use this programmer all the time at my work for programming 27c1024 chips and 29c512 chips. Usually when we can't get a chip to program, we just grab another, but since i only have 2 of the 27sf512, I'm kind of stuck now. We actually have 2 chipmax programmers, so maybe I'll try the other one, but I'm kind of leaning towards bad chips. I've read posts on this forum where people have gotten 4 chips and all 4 were bad.

 

Oh, looks like the little bit I found on the internets about the ChipMax was not really accurate with regards to your setup (I had assumed that the SST27SF512 was not in the list of options). So, you can pretty much disregard everything I said in my previous post.

About the bad chips... I have two of them here too and they are both bad as well. I think I over-volted them though, I have a programmer w/ adjustable voltage and when I first started programming I set the voltage with a very old and apparently inaccurate voltmeter. What I thought was 12v ended up being around 14v. So, I never really knew for sure if they were bad from the start or if I killed them...

It kinda sucks though cause the SST27SF512's have been discontinued, and are getting to be like $5 apiece...

But, yeah, I guess I would have to lean toward bad chips as well in your case.

 

After thinking about it for a while, i checked to see if there was any newer software available from eetools for the chipmax programmer and there was! The latest release was less than a week ago. I was using an much older version of their programming software (it was running on DOS). Installed the new software on XP and hooked up the programmer and I was able to program and verify. I haven't tried the chips in my car yet, but it looks like I should be good to go.