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Name: t400
Created: May 5, 2006
Updated: Aug 19, 2009
SVN Updated: May 28, 2009
SVN: Browse
Latest version: download (might take a bit to start...)
Statistics: View
Bugs: 1 reported / 1 solved
Star1you like it: star it!

Other project properties

Development status:Stable
Additional info:Design done, FPGA proven
WishBone compliant: No
WishBone version: n/a
License: GPL


The T400 µController is an implementation of National's 4-bit COP400 microcontroller family architecture. It is intended to be used as a replacement for the original chip in SOCs recreating legacy systems.

Its final target is to provide design variants that are compatible with the COP420/421 and COP410L/411L family members. All of them derived from the common t400_core design. Such a sample system has been implemented in several FPGA families.

  • COP421-like features
  • 64 bytes internal RAM
  • 1024 bytes internal ROM (only small part used for program)
  • 4 MHz required performance

The implementation has been done with the free version of the vendor tools (Quartus II 7.2sp3 and ISE 10.1). Your mileage may vary.

Altera EP1C12Q240C8:

  • 583 / 12060 Logic Elements
  • 8,448 / 239,616 Memory Bits (RAM & ROM implemented in memory block)
  • 59 MHz maximum registered performance

Xilinx Spartan-IIE XC2S300EPQ208-6:

  • 643 / 6144 Logic Cells
  • 2 / 16 Block RAMs (RAM & ROM implemented in memory block)
  • 60 MHz maximum registered performance

The T400 µController has been successfully integrated in the FPGA Adventure Vision project.


The following tools are integrated and are required for this project:

  • The Macro Assembler AS
  • The GHDL simulator
  • The Perl scripting language


The project has Stable status:

  • All of the targeted functionality is implemented in synthesizable VHDL.
  • Verification suite is available containing self-checking assembler patterns for all implemented instructions.
  • All instructions implemented and verified with black-box tests.
  • Toplevel system designs resembling COP420, COP421, COP410L and COP411L are available and verified with regression test suite.
  • Proven synthesizability for different FPGA families.
  • Stable interfaces for internal modules.

Known bugs will be logged on the Tracker page. Please feel free to enter any problems you encounter with this core.


The COPS Family User's Guide and the specific datasheets can be downloaded from DatasheetArchive.


The latest release of the T400 µController project is version 1.1.

Get this and all previous versions of the design files from SVN: Download repository.

Please keep in mind that trunk/ is work in progress and might contain smaller or bigger problems.

You should also check the Tracker for known bugs and see if they affect your work.