Embedded Soft Processor Core
The proposed architecture utilizes the open source plasma
MIPS processor [5]. It utilizes the MIPS-I instruction set.
Here, the RTL code is released under a public domain license.
A GNU C toolchain for compiling software is available to
designers. An open source core allows greater flexibility in
design since user can modify the operation consistent with the
requirement. The structure was altered to remove the use of
external SRAM, and reduce the need for external hardware.
To provide the necessary memory, 64Kb of the FPGA OnChip memory for the program and data memory was used.
The Plasma’s General Purpose Input/Output (GPIO) pins
provide interconnects to other internal modules on the FPGA
hardware pin on the FPGA so that interfacing is possible with
external devices .
The root processor is responsible for host communication,
performing housekeeping tasks, and controlling external devices (ADC’s,LNA’s, etc) with register configuration. The
registers are mapped to the root processors memory in the
FPGA through an address decoder.