  We demonstrate a novel architecture for Adaptive Optics (AO) control based on
FPGAs (Field Programmable Gate Arrays), making active use of their configurable
parallel processing capability. SPARC's unique capabilities are demonstrated
through an implementation on an off-the-shelf inexpensive Xilinx VC-709
development board. The architecture makes SPARC a generic and powerful
Real-time Control (RTC) kernel for a broad spectrum of AO scenarios. SPARC is
scalable across different numbers of subapertures and pixels per subaperture.
The overall concept, objectives, architecture, validation and results from
simulation as well as hardware tests are presented here. For Shack-Hartmann
wavefront sensors, the total AO reconstruction time ranges from a median of
39.4us (11x11 subapertures) to 1.283 ms (50x50 subapertures) on the development
board. For large wavefront sensors, the latency is dominated by access time (~1
ms) of the standard DDR memory available on the board. This paper is divided
into two parts. Part 1 is targeted at astronomers interested in the capability
of the current hardware. Part 2 explains the FPGA implementation of the
wavefront processing unit, the reconstruction algorithm and the hardware
interfaces of the platform. Part 2 mainly targets the embedded developers
interested in the hardware implementation of SPARC.
