Research of PE Array Connection Network for Cool Mega-Array

A Cool Mega Array or CMA is a low power reconfigurable processor array for battery driven mobile devices. We developed a prototype chip CMA-1. It is consisting of the 8 x 8 PE array, μ-controller for controlling data alignment and data memory. We just borrowed the PE array network of a dynamically reconfigurable processor for theCMA-1, and sufficient examination about it has not been carried out so far. The overhead of the configuration data transfer time to the CMA-1 also appeared to bottleneck the system performance. It means that the quantity of configuration data for the PE array should be as small as possible. In this paper, we proposed and evaluated three types of the CMA which PE array networks are different respectively in order to clarify the PE array network which is the most suitable for the CMA. As a result, in the CMA-cons which has island-style interconnection and dedicated links for sending constants, we could reduce the number of steps for transferring configuration data by 44.4% on average, 53.8%at most without a negative influence on performance and power consumption of the CMA.