  Scan and ring schemes of the pseudo-ring memory selftesting are investigated.
Both schemes are based on emulation of the linear or nonlinear feedback shift
register by memory itself. Peculiarities of the pseudo-ring schemes
implementation for multi-port and embedded memories, and for register file are
described. It is shown that only small additional logic is required and allows
microcontrollers at-speed testing. Also, in this article,are given the a
posteriori values of some type of memories faults coverage when pseudo-ring
testing schemes are applied.
