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Help on thermometer decoding implementation in DAC

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I am designing an 14-bit DAC. To compensate the systematic gradient errors, i need to control the switching sequence of the MSB current sources.

I am refering to the paper "A 14-bit Intrinsic Accuracy Q^2 Random Walk CMOS DAC"

But I am not quite clear how it implement the decoding logic with a special VHDL implementation using lookup tables.

Anyone know the details?
 

I am wondering the classic column-row decoding scheme can also be applied to randomized current source layout.

Added after 4 hours 42 minutes:

yeah! I have got that.
suppose we adopt N bit unary in MSB

The sequence to turn on this current source can be represented as
Sequence=2^(N/2) * row + col

row is from 0 to 2^(N/2)-1
col is from 0 to 2^(N/2)-1

In random sequence, we can get row/col from the "Sequence".

row=[Sequence/(2^(N/2))] [] means get the integer part of the result.
col=Sequence%(2^(N/2))

So even for randomized current source as presented in the above paper, we can still use the row-column decoding scheme!

Aha!
 

I have questions on this paper.
The first is how do u get the real "randomized" switching sequency.
The second is by what method the author get the residue errors distribution in matlab.
I have read this paper and the paper "A 12-bit intrinsic accuracy high-speed CMOS DAC" for countless numbers but still can not understand the above two problems.
could anyone give me some advice?
 

Those papers always brief out the most important contents. :(
 

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