After 3 cups of cofee and few hours of looking I think that finally I'm getting to understand that algorithm. Correct me if I'm wrong.
A to H are 32bit variables with 0h00000000 value at the begining. Wt and Kt are input values (data and nonce in terms of bitcoin?) After all operations (Ch function, Ma function, sigmas, modulo additions) result is moved to variable A and rest of them are moved one position. This happens 64 times and result of SHA256 operation is in A to H registers. Only unknown to me is that strange operand in Ch function (before second E). Is it NOT operand? Its not listed in table beneth.