README

Overview

The IP implements a basic 8-bit microcontoller that reads custom assembly code from an external ROM and performs the corresponding microinstructions. RTL and testbenches are written in SystemVerilog.

• Includes a full-duplex UART with DMA capabilites.
• Internal memory is divided into register space and general purpose memory.
• The CPU can decode instructions of 1-byte and 2-bytes.

Requirements

The project makes use of Makefiles to build targets for setup, elaboration, simulation and synthesis.

Icarus Verilog

Icarus Verilog is a Verilog simulation and synthesis tool that supports a good number of SystemVerilog constructs.

To download the latest version from GitHub: https://github.com/steveicarus/iverilog

Verilator

Verilator is a free and open-source software tool which converts Verilog to a cycle-accurate behavioral model in C++ or SystemC. However, in this project it is used only to perform additional extra linting checks.

To download the latest version from GitHub: https://github.com/verilator/verilator

Vivado

Synthesis has been tested with Xilinx Vivado 2018.3.

Some scripts expect its installation folder to be at /opt/Xilinx/ if project creation for synthesis targets are being run.

Elaboration, simulation and synthesis

To elaborate/simulate all the submodules and hierarchy top module:

$ make all_elabs
$ make all_sims

To elaborate/simulate an standalone submodule:

$ make top
$ make tb_top

Waves will be created at the waves folder.

To synthesize the IP first a Vivado project needs to be created. To recreate it a TCL is provided. To run its target:

$ make vivado_proj

To synthesize the IP:

$ make vivado_syn

Known Issues

Since Icarus Verilog does not have support for SystemVerilog interfaces as module ports, object oriented class-based testbench is not possible. A free alternative would be Vivado 2018.3 WebPack Edition. Includes a license for device xc7z010clg225 (Zynqberry's FPGA), and supports SystemVerilog virtual interfaces. As a drawback, simulation seems much slower than with Iverilog.

Formal verification with SimbiYosys is not possible either as it does not support SystemVerilog.