help with Xeltek EPROM programmer

I have a Xeltek Superpro/Z eprom programmer, with their winsp ver. 1.0 software, running on Win 2K/Pro. Today I had need to erase and reprogram an Atmel 17LV256 EEPROM, but the erase button on the programmer GUI is grayed out.  I can't remember if I ever did this before.  I used to use UV-erasable EPROMS, but this one is electrically erasable. Is there a setting or option that enables erasing?

(I know if I try to contact Xeltek, they will try to sell me a new programmer.)

Thanks in advance for any hints!

Jon

You fill the buffer with 0xff and write the buffer. Now it's 'blank' Same for any EEPROM

I tried just re-writing the EPROM, and it gets an error within a second or two. I will try writing an all-zero block and see what happens.

I'm pretty sure this device cannot be byte-erased.

Jon

Most, if not all EEPROMs automatically do an erase before write..... so just program it.... Good job it's not a 17V16- they're OTP :( We use those for military stuff... pain in the bloody butt...

Then I already know that does NOT work. it gets an error, which I'm guessing is that the bits are already programmed to the program state, and need to be reverted to the non-programmed state. Yeah, I switched to this Atmel device to get away from the expensive Xilinx 17xxx (OTP) parts. They are not only cheaper, but are supposed to be re-programmable. What I'm worried about is the Xeltek may not have suitable voltages available to do the erase. or, maybe, that is an extra-cost option for the programmer! Sheesh, this stuff shouldn't be so complicated. But, I can't believe I've had this thing for about 10 years and NEVER noticed I can't erase one of these parts!

Thanks,

Jon

WOW! I think I got my answer, and my face is RED!

Atmel calls this an EEPROM, and I always thought that meant Electrically-erasable, Electrically-Programmable ROM. But, I read the whole datasheet, and NOWHERE at all does the word erase appear! So, apparently the 17LV256 family are all OTP devices! Geez, I've been using them for a number of years, and had NO idea they were OTP!

Jon

Funny manner of OTP part that has a write-protect pin on it... Just say'in.

The reset pin polarity is programmable too, which might be an interesting source of issues on non-virgin parts.

Best regards, Spehro Pefhany

I always liked the parts that have I2C addresses that are programmable, over I2C. ;-)

Generally, EEPROMs do not have to be erased like flash. You simply write the new value. I do not think these devices are OTP as the data sheet says they are good for 100K write cycles. Your errors may be caused by the programmer not handling the WP pins correctly.

Yup- if you're going to make a product with no front panel that allows you to change the IP address via an Ethernet connection, better put a visible clearly marked reset switch to return it to a clearly marked default value.

Best regards, Spehro Pefhany

Yup, the write protect prevents the contents from being altered further. But, I can't find ANYWHERE that mentions how to erase the part!

Jon

Well, you guys are all 100% CORRECT! I still don't know what happened, maybe there was a dirty spot on the programmer's socket. But, I went back and tried programming the device, and it worked perfectly! That's why I never noticed the erase button was grayed out, I never used it before, I just reprogrammed the part and it worked.

Thanks, everyone!

Jon

Usually such equipment comes with software which allows to reset the IP address. Its not difficult to send a 'proprietary' protocol over an ethernet network.

Excellent result in the end, unlike me who has been trying to persuade Dataman that their programmer won't overprogram two of the config bits in the 17V16. Bought two more in the end as the project timing is critical with late delivery penalties.

Don't think there's any alternative in the military spec part... unless anyone knows different... 17V16 CC44M