Modularized architecture of address generation units suitable for real-time processing MR data on an FPGA.

In this paper, we describe a modular approach to the design of an Address Generation Unit (AGU). The approach consists of development of a generic Address Generation Core (AGC) as a basic building block and the construction of an AGU from the AGCs. We illustrate this concept with AGUs capable of handling 2D- and 3D-structured data, and as well as their setup for executing 2D and 3D FFT algorithms on a Field Programmable Gate Array (FPGA). The AGUs developed using our proposed method are simple and easily expandable. Furthermore, they can potentially support irregularly structured data which are often generated from the wide variety of pulse sequences in magnetic resonance imaging. Our experimental results show that these AGUs are capable of generating addresses with a user-predefined pattern automatically at the speed of one address per clock cycle and operate at clock rates up to 80 MHz. They can operate concurrently with other processes and thus do not introduce additional operation latencies. Although we focus on applying the developed AGUs to executing 2D and 3D FFT, we expect that the modular design method should have much wider applications.