specs/data.md

@@ -1,32 +0,0 @@
-# Data card
-
-The data card deals with binary data, thus there must be a simple format.
-
-## Hamming ECC
-
-Each nibble (4-bit sequence) uses a Hamming (7, 4) code encoded in 1 byte, with the ability to detect 2 bit errors (but not correct them)
-
-Given N bytes to encode, the final encoded output will take 2N bytes.
-This also means when decoding, the length must be even.
-
-A byte is split into 2 nibbles, with the one comprised of the lowest bits first.
-Each nibble is ECC encoded separately.
-In a nibble there are 4 bits d0, d1, d2 and d3, from lowest to highest.
-In the output, there are p0, p1, p2, p3 bits, where p1 and above represent hamming code parity data, and p0 is a parity check on the whole block.
-
-### Nibble arrangement
-
-```
-| d0 | d1 | d2 | d3 |
-```
-
-### Hamming code arrangement
-
-```
-| p0 | p1 | p2 | d0 |
-| p3 | d1 | d2 | d3 |
-```
-
-The bits are arranged such that p0 is the lowest bit and d3 is the highest.
-
-This creates a fairly generic hamming code structure. Do note that p0 is the bit for checking the whole block's parity.