The aims of this project
are:
-
Define an architecture for an embedded RISC
microprocessor.
-
A scaleable acrhitecture from 16 bit to 32 and even
8 or 64 bit.
-
Style of architecture somewhere between a PIC(MicroChip)
and a SH(Hitachi).
-
Implement the processor in a HDL form (VHDL or Verilog)
than can be synthesised to FPGA or a standard cell ASIC.
-
Use of standard PROM and SRAM for program and data
memories (not dual port or synchronous).
-
Simple single clock cycle instructions where possible.
-
Interrupts if possible
-
16 bit instructions (as SH or ARM-Thumb)
for all data widths.
-
Support tools such as an instruction set simulator
and assembler are required to exersize the design and allow simple applications
to be written.
These have led to a number of design descisions:
-
Separate instruction and data memory buses.
-
Simplify design at expence of size of core/code size/power etc.
-
Reduced arithmetic operators (no multiply yet).
-
Load store architecture with lots of registers (say
16).
-
Use one of the general purpose registers as the stack
pointer.