CPU review: openMSP430, Plasma, T400 and T48.

The study items are listed on the Open Source CPUs post, especially the category description.

Let’s have a look at OpenCores Certified processor Projects.
OpenRisc1000 is already done.


This is a clone of TI’s MSP430, a 16bit micro-controller. Just by this it’s a tiny micro-controller again…
Also it’s a clone again, there is a port of GCC for the MSP430 family: mspgcc.


This on is a Mips-like, that is to say it has most MIPS I instructions except the patented one (the page says the patent expired, so one could probably add them, need to check the legal stuff, remember I’m no legal expert).
Well it work, is still serving a website so great ­čśë
It does not look like there is any MMU, so it’s an embedded CPU.

T400 ┬ÁController

An implementation of a legacy cpu again… clone of National’s 4-bit COP400 microcontroller.
The distribution include a GPL V2 text but the header in the vhdl files does not refer to GPL but gives a rather more permissive licence (looks BSDish to me) especially allowing synthesized work to be distributed without the source…
As for the category, it’s a 4bit cpu remember, so a tiny micro-controller.

T48 ┬ÁController

This is a MCS-48 microcontroller clone. The licence is the same as T400 above (it’s the same author).
A 8bit micro-controller that will continue to flood the tiny micro-controller category.

As usual the summary table is there: Open Cpu Study Summary.

2 thoughts on “CPU review: openMSP430, Plasma, T400 and T48.

  1. Olivier

    Thanks for the review ­čÖé

    You forgot to mention one of the differentiating factor for the openMSP430: its serial debug interface (enabling GDB support of the mspgcc toolchain).
    You should probably add this category in your study summary as it is really a critical feature for in-system embedded software development.


  2. Julien Post author

    Yes remote debugging with GDB is a nice feature, but I was not going into such details, checking the license was the goal of this first line of study, than I think depending on the result I might select some CPU and go into more details (I might even tests some on both simulation and FPGA). Some more columns will be added to the summary at this time ­čśë
    I must tell that your message is showing that your project is still live, which is important for new users to get support if needed.

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