Method for implementing functional changes into a design layout of an integrated device, in particular a system-on-chip, by means of mask programmable filling cells

A System-on-Chip (SoC) may include logic blocks connected to each other and to external connections, and a hardware debug infrastructure logic connected to the logic blocks and for performing functional changes to a design layout of the SoC. The hardware debug infrastructure logic may include software re-configurable modules based upon the logic blocks obtained from substituting a mask programmable ECO base cell configured as a functional logic cell for a logic cell in the design layout.