Basic principles  of operation are shown for a single cycle of information processing in a spin-echo processor. The approach is a generalization of matrix, diagram, and algebraic ways to calculate the dependence of echo-signal parameters on the parameters of data and control pulses in an excitation sequence. The single cycle operation structure is shown. Notions of data registers and input data operators are introduced. The approach permits one to trace information transformations in a multi-channel register structure of the spin-echo processor and to find optimal conditions for reading the results at its output.