Hardware-software codesign with GRAPE

GRAPE-II (Graphical Rapid Prototyping Environment-II) is a hardware-software codesign environment for the real-time functional emulation of synchronous DSP systems. It allows one to specify the application's data dependency graph in a target-machine-independent way. After specifying the heterogeneous target machine's architecture, it estimates the resources needed by each application subtask. Based on these requirements, it assigns the subtasks to specific target devices at compile-time, be they processors or FPGAs, establishes routing paths and determines a static schedule. It generates a main shell for each target device and generates intra-device and inter-device communication code. After downloading the executable images on to the target machine, it allows the designer to modify end-user controls and application settings at run-time. This paper situates the tool in the application design cycle, explains GRAPE-II's design flow and shows the advantages of hardware-software codesign by evaluating the achievable sampling frequency for a small example application.