Design and Verification of Apb Bridge

Abstract

Semiconductor chips use a wide variety of communication protocols. Not all applications require a high-speed bus protocol. APB (Advanced Peripheral Bus) protocol from AMBA (Advanced Microcontroller Bus Architecture) family is an excellent choice where speed is not desired. APB protocol allows the address on this address bus to be unaligned to the width of the data bus. APB slave which receives this read/write request might not be capable of handling unaligned addresses. Its result might be unpredictable. This paper helps solve this limitation in the slave by adding a bridge that converts requests with an unaligned address from the master to two separate requests with addresses aligned to the data bus. Developing this bridge helps in reusing the APB slaves (which do not support unaligned addresses) and APB masters (which issue unaligned addresses). Using this bridge helps designers save a lot of time and energy which otherwise is spent making changes in APB slaves to support unaligned addresses or APB master to only send aligned addresses. And, to make sure that the bridge behaves as expected, verification is important. This paper talks about developing a verification environment using UVM (Universal Verification Methodology), which is reusable and easily manageable.