Register protection circuit for hardware ip modules

Abstract

A protection module for an electronic circuit prevents unintended write operations by a master module to functional registers of a protected module. The protection module includes soft lock bits (SLBs) that indicate whether corresponding functional registers are locked and control logic that supports (i) a page select (PS) control parameter that indicates whether access by the master module is to the functional registers or the SLBs and (ii) a mode select (MS) control parameter that indicates whether access by the master module to the functional registers is in a normal access mode, in which each written-to functional register is left unlocked, or an auto-lock access mode, in which each just-written-to functional register is automatically locked by setting the corresponding SLB. The functional registers and the SLBs share addresses that can fit within a single address space that includes the control parameters.