This technical memorandum presents a unified framework for the study of anti-windup designs in linear time-invariant (LTI) systems subject to control input nonlinearities. The framework is based on a two-step design paradigm: first, design a linear controller ignoring control input nonlinearities, then add anti-windup bumpless transfer (AWBT) compensation to minimize the adverse effects of these nonlinearities on closed-loop performance. The resulting AWBT compensation is applicable to multivariable controllers of arbitrary structure and order. All known LTI anti-windup and/or bumpless transfer compensation schemes are shown to be special cases of this framework. The framework handles standard issues such as the analysis of stability and performance with or without uncertainties in the plant model. The main result is the unification of existing schemes for AWBT compensation under a general framework. The paper discusses the problem of control system analysis and controller synthesis for the general class of LTI systems subject to plant input limitations and substitutions, referred to as the anti-windup bumpless transfer (AWBT) problem. It reviews existing approaches to solving the problem of control of LTI systems subject to control input nonlinearities, which involve designing a linear controller and then adding AWBT compensation. While many of these schemes have been successful in specific SISO situations, they are largely intuition-based and have little theoretical foundation. The paper presents a general framework for studying anti-windup and bumpless transfer designs, showing that all known LTI anti-windup and bumpless transfer schemes are special cases of this framework. The framework is shown to handle standard issues such as the analysis of stability and performance, with or without plant uncertainty. The paper concludes by discussing the implications of the framework for the design of anti-windup compensators.This technical memorandum presents a unified framework for the study of anti-windup designs in linear time-invariant (LTI) systems subject to control input nonlinearities. The framework is based on a two-step design paradigm: first, design a linear controller ignoring control input nonlinearities, then add anti-windup bumpless transfer (AWBT) compensation to minimize the adverse effects of these nonlinearities on closed-loop performance. The resulting AWBT compensation is applicable to multivariable controllers of arbitrary structure and order. All known LTI anti-windup and/or bumpless transfer compensation schemes are shown to be special cases of this framework. The framework handles standard issues such as the analysis of stability and performance with or without uncertainties in the plant model. The main result is the unification of existing schemes for AWBT compensation under a general framework. The paper discusses the problem of control system analysis and controller synthesis for the general class of LTI systems subject to plant input limitations and substitutions, referred to as the anti-windup bumpless transfer (AWBT) problem. It reviews existing approaches to solving the problem of control of LTI systems subject to control input nonlinearities, which involve designing a linear controller and then adding AWBT compensation. While many of these schemes have been successful in specific SISO situations, they are largely intuition-based and have little theoretical foundation. The paper presents a general framework for studying anti-windup and bumpless transfer designs, showing that all known LTI anti-windup and bumpless transfer schemes are special cases of this framework. The framework is shown to handle standard issues such as the analysis of stability and performance, with or without plant uncertainty. The paper concludes by discussing the implications of the framework for the design of anti-windup compensators.