There are four modes of SPI relating to clock edge, phase, and clk polarity. Have you tried all?
I'd like to dump the contents of a Toshiba TC58CVG0S3HRAIG 1Gbit NAND flash IC. Since it's a WSON form factor IC, unsoldering without damage to the surrounding circuit is going to be near impossible with the tools & equipment available to me. It'll have to be read in-circuit. I've been told the embedded processor (MCU) can be held in reset which should place all lines in a hi-Z state, and not load down the SPI interface of the flash, making it free to read. Hmm, not 100% convinced yet, but I'll give it a try.
I tried doing exactly that, soldering fine wires on to the flash IC pins (except Vcc, let the circuit it was attached to power the flash) and then connecting them to a carrier PCB and in to my little CH341a USB flash reader/writer. It struggled to read, restarting the read several times, and took >15 minutes to complete a read when it did manage one pass OK. The resulting read was a complete failure though, returning random data, certainly not the contents expected. I'm guessing, then, the normal serial flash SPI and a NAND flash SPI are somehow different?
What (cheap!) hardware & software could be used to read a TC58CVG0S3H series NAND flash?
Look Here -> |
There are four modes of SPI relating to clock edge, phase, and clk polarity. Have you tried all?
Didn't know that, but in any case the software for the little CH341a programmer doesn't have those options. It might select them in the background when you select the specific chip type to program or read, but does have an option for 'unspecified' which I tried, and didn't work. It had no Toshiba 25/26 SPI Flash types in it's option list to try either.
Have you looked at the MLAB Software and Pickit 3 Programmer ?
mitaux8030 (17-09-18)
Last edited by mitaux8030; 17-09-18 at 02:41 PM. Reason: Adding extra information
Perhaps you will find the article at useful.
Alternatively, explore some of the results from .
The problem for me isn't the physical connection - this is a serial NAND flash chip with only 8 widely spaced pins. The issue is that due to it's WSON form factor where the solder pads extend quite some way underneath the body of the chip, unsoldering is going to be impossible with the resources I have access to. That means the chip will need to be read in-situ, and it appears as if either other devices on the bus are loading the flash chip down, or my SPI flash reader isn't compatible with this SPI interface on the serial NAND flash chip?
Just a thought here but what I've encountered in the past is simple encryption schemes like inversion or XORing used to prevent easy reading of data from fixed memory. If your successful reads are all identical but it still looks like random data then it's a possibility.
Last edited by Skepticist; 24-09-18 at 12:49 PM.
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