Interesting memory idea

Conundrum, Sat Mar 24 2012, 03:12PM

Hi all.
Given that microSD cards are so easy to lose, and the upcoming nanoSD standard (80% microSD length, 25% width)
why don't these cards just include an RFID chip and be done with it?
The RFID could be one of the chip layers, at the top of the stack increasing thickness by only 0.1mm.
As chip level RFID's are well known this should be a simple and cheap modification.

The chip could also be used to store the decryption key like a normal Bluray or DVD, and when commanded output direct DVI/etc data over all of its pins with power over RF so it can be plugged directly into a TV with a simple adaptor.
Adaptor would need some extra circuitry and an RFID reader/power but its doable.
This is feasible due to the low power consumption of flash during reading, <5mA in most cases.

Due to the power and clock being provided via RF there would be no need for large pins, only a ground which is around the entire lower edge of the chip to ensure reliable connection and the eight data pins arranged in a linear line as in the current standard.
Suggest using a resistor colour code on the top of the card to show capacity directly and card speed.
i.e. brown blue red gold would indicate 32GB class 10.

Regulator would be shifted externally to the card allowing old systems to read/write nanoSD but with a far lower chance of frying
the card(s) with excess voltage.

These cards would be backwards compatible with microSD with an adaptor, 3 cards per unit (!) and with 32GB per card thats nearly 100GB in something that fits in most phones made now.
Switching between cards could be as simple as selecting using the RFID and then reading the appropriate data from each card.
The reader would need a small amount of memory to store the filesystem but it would be triple redundant and if two out of three cards failed then only the data on them is lost and not the whole archive.
Also it would be tougher against accidental deletion and overwriting as the filesystem would be backed up on each card and the reader, and only written if all cards signal that their section of the CRC32 matches.

The reader could also use a tricolour LED to indicate cards inserted, with white indicating all working.
This could also change brightness to show write progress etc, and flash if there is a problem with a given card.
The multiple chips could also be used in RAID form to overcome slow write speeds, so lower cost 3 bit/cell stacks could be used.
While one card is writing the other two can write the next sectors, so for large movie files etc the speed would increase far above even Class 10.

For embedded devices such as pendrives and phones where the memory needs to be permanently secured, the chip(s) can simply be heat bonded with conductive Z axis tape directly to the PCB.
No soldering needed, and very resistant to tampering.


Comments?