Overview

A simulator for the NED architecture.

Status

The CPU simulation is complete except for the CMPSWP instruction. Only a single CPU is currently supported.

A UART-like console is included with the following register layout:

0x8000000 - Transmit Buffer - Accepts bytes and prints to console
0x8000004 - Transmit Status - Non-zero when UART is ready to accept a character.
0x8000008 - Receive Buffer  - Contains a byte from the console when available.
0x800000C - Receive Status  - Non-zero when UART contains a character.

Installation

Use make and make clean to build/remove nedsim files. System installation requires manually copying the binary in to place.

What configuration is available can be found as #defines at the top of the nedsim source code. This includes things like size of system RAM, number of hardware threads, etc.

Operation

Use nedsim -h to see current command-line options.

The simulator will terminate if a HALT instruction is reached and can also be terminated during operation with Ctrl-C.

The nedfp program provides a passive front panel compatible with nedsim.