EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: ali6x944 on January 14, 2017, 03:13:04 pm
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HI everyone,
is it possible to hack the SoFi technology SP8 programmer to work with 27 series EPROMs?
I know it is kind of weird knowing that the SP8 is a serial programmer, i don't need to program them, i only need to read them ...
thanks a lot for all the help
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Probably not; parallel devices are so easy to read it'd probably be easier to set up an Arduino Mega or another dev board of your choice with enough IO to do it.
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Can I do it with an uno?
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Can I do it with an uno?
The Uno has 20 I/O pins in total I think; and the EPROM will need A+8 IO lines to read - where A is the number of address lines - as CS can be hardwired low. This means with the Uno alone you could read anything up to and including a 27C32. For larger devices you would need to add hardware such as an IO expander; shift registers; or a counter on the address lines to increase the number of available IO.
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I like the IO Expander idea for the address lines. Personally, I prefer SPI but Microchip makes both SPI and I2C 16 bit expanders
http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf (http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf)
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I like the IO Expander idea for the address lines. Personally, I prefer SPI but Microchip makes both SPI and I2C 16 bit expanders
http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf (http://ww1.microchip.com/downloads/en/DeviceDoc/21952b.pdf)
parallel expansion?
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3 octal latches, a latch line for each and recycle the data bus, and you can read anything up to the maximum they ever made EProm in. You just need a /cs line for the prom to read it, and this only needs one port as data bus, and 4 bits off the others to drive the logic. Add in 3 extra lines and a high voltage generator to supply Vpp and you can write to them as well, and it is random read or write as well. Another 2 lines for selecting Vdd and you can verify fully as well, or check for bit rot.
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I will see in my parts box and see...
I think I had an octal D latch, and some of the parts u mentioned...
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Are 74ls374 ok for the octal latches?
For the hi programming voltage l will use a computer psu..
Any other things I might add?
I also I contacted sofi about and they replied by saying they can't do anything about it...
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Are 74ls374 ok for the octal latches?
For the hi programming voltage l will use a computer psu..
Any other things I might add?
I also I contacted sofi about and they replied by saying they can't do anything about it...
According to the datasheet I just read, the logic input 1 voltage for the latch can be as low as 2V. It will also work with the EPROM. So, the 3.3V Arduino can send signals to these devices.
Where you might have a problem is the fact that the EPROM output voltage can be higher than a 3.3V Arduino wants to see. You could try putting some resistors in series with the data signals. I don't know what size and I wouldn't recommend it anyway.
So, get a 5V Arduino and keep everything at the same level. This Pro Mini is 5V and there are others:
https://www.sparkfun.com/products/11113 (https://www.sparkfun.com/products/11113)
For this board, you need some kind of programming adapter like this:
https://www.sparkfun.com/products/9716 (https://www.sparkfun.com/products/9716)
Notice that the device puts 5V out onto the programming header so it will power the Arduino from USB if you wish. There's a jumper to select that voltage, see the schematic.
I might not use that 5V supply working with a box of parts like this. I would rather protect my PC. So, I would cut the jumper (or somehow prevent the adapter from providing +5) and power the project with a 5V wall wart.
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Are 74ls374 ok for the octal latches?
For the hi programming voltage l will use a computer psu..
Any other things I might add?
I also I contacted sofi about and they replied by saying they can't do anything about it...
According to the datasheet I just read, the logic input 1 voltage for the latch can be as low as 2V. It will also work with the EPROM. So, the 3.3V Arduino can send signals to these devices.
Where you might have a problem is the fact that the EPROM output voltage can be higher than a 3.3V Arduino wants to see. You could try putting some resistors in series with the data signals. I don't know what size and I wouldn't recommend it anyway.
So, get a 5V Arduino and keep everything at the same level. This Pro Mini is 5V and there are others:
https://www.sparkfun.com/products/11113 (https://www.sparkfun.com/products/11113)
For this board, you need some kind of programming adapter like this:
https://www.sparkfun.com/products/9716 (https://www.sparkfun.com/products/9716)
Notice that the device puts 5V out onto the programming header so it will power the Arduino from USB if you wish. There's a jumper to select that voltage, see the schematic.
I might not use that 5V supply working with a box of parts like this. I would rather protect my PC. So, I would cut the jumper (or somehow prevent the adapter from providing +5) and power the project with a 5V wall wart.
I have a USB to UART converter but it is not a FTDI, mine is a silicon labs CP2102, I think it will be ok..
For the arduino can I use the bare chip?
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I also bought a clone arduino uno, it could replace both the usb to uart bridge and the chip I guess...
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Now what is next??