Eprom programing with ardunio.

Mr.Alan

Joined Aug 15, 2016
14
Hi. Im trying to program my eprom that i got from my random ic bag. Im now experimenting with digital electronics and i have learned basics of eprom and digital electronics. Programing a eprom sems complicated and i want to realy know if there is any easy way to program my eprom with a ardunio? The eprom i have is M27C512 from the ST company.

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Dyslexicbloke

Joined Sep 4, 2010
559
Well you are going to need 3 supplies, one for the Arduino and two for the memory.
You also need 24 outputs from whatever device you are using to program the thing.

You need to do some reading but basically

All address and data pins need to be pulled low and all data pins pulled high @ 5V to be safe...
NOT E also needs to be high.

You supply the chip with a slightly higher than normal voltage, 6.25v
Apply a programming voltage to Vpp @12.75V

Apply an address and a value then pull NOT E low for a short period and then released.
Increnent the address, apply the new data and pull NOT E down again.

Do this fore all the registers you want to set to anything other than 1111111111111111
You should verify each cycle by releasing the data lines, back to 5v, and then pulling NOT G low, if the register is good the data lines should go low as they would when reading (At least I think that is correct, you should check)

As I said, read first but dont get frightened off it isn't too hard by the look of it.

You will only be writing 0's but as you only get one chance to do it make sure you dont leave anything floating on either bus.

I haven't done anything like this fore at least 30 years but I dont remember it being too tricky.

You might want to considder an EEPROM to play with, they can be errased / overwritten electrically and will only require 5 volts to work with.
It avoids all that pesky mucking about with UV boxes or putting chips in the bin when you make a mistake on an OTP device.

If you only have an Arduino with limited IO you could use shift registers to set address and data, essentally using two pins to strobe out the the 24 bits you need.

Hope that helps,
Al

dl324

Joined Mar 30, 2015
10,751
Programing a eprom sems complicated and i want to realy know if there is any easy way to program my eprom with a ardunio?
It will take a combination of the Arduino and hardware. Programming will require several different voltages; 6-6.25V plus 12.75V for programming, 5V for program verification, and 4.2-4.45V for blank verification.

You can implement a dumb algorithm (not recommended), or use one of the smarter algorithms that speed up programming.

This is the typical algorithm:

ian field

Joined Oct 27, 2012
6,539
Hi. Im trying to program my eprom that i got from my random ic bag. Im now experimenting with digital electronics and i have learned basics of eprom and digital electronics. Programing a eprom sems complicated and i want to realy know if there is any easy way to program my eprom with a ardunio? The eprom i have is M27C512 from the ST company.
There might be a shield for that - most of the 80s/90s home computers could be fitted with an EPROM card/peripheral.

If you're going the DIY route - you need to take care with Vpp. There were various technologies each with their own critical Vpp specification.

MMcLaren

Joined Feb 14, 2010
842
I built a programmer long ago for a very small subset of 12.5v EPROMs. I used a 15vdc power brick and just two pins to manage power to the target devices. If I recall correctly, here's how I controlled the power;

Code:
   Input     Output
PWR PRG   VCC  VPP
--------------------
1   1    off  off
0   1    5.0  5.0
0   0    6.5 12.5

Last edited:

ian field

Joined Oct 27, 2012
6,539
I built a programmer long ago for a very small subset of 12.5v EPROMs. I used a 15vdc power brick and just two pins to manage power to the target devices. If I recall correctly, here's how I controlled the power;

Code:
   Input     Output
PWR PRG   VCC  VPP
--------------------
1   1    off  off
0   1    5.0  5.0
0   0    6.5 12.5
View attachment 128836

View attachment 128837
The old Apple II card used a switch mode converter from the5V rail.