I hope all of you are enjoying FSS Version_0-006, which I released 2007-05-13.

Right after release, I went to work on the installation instructions and instructions for using the postsimulation application. I used a computer that had never seen the FSS application suite before to discover the dependencies. It took me until 2007-06-03 to complete those instructions.

I then made several software improvements before getting back to that with which I wanted to play, integer multiplication. You will see these improvements when I release Version_0-007.

I made the postsimulation application more robust and gave it the capability to transparently perform some database cleanup.

Attempting to Load 1 Program, then canceling, causes NullPointerException. I fixed that.

I observed an address sorting problem in the memory view with the high half of the address space (i.e. addresses whose most significant bit is 1) and fixed that. The solution had to do with using
in more places. By the way, my accepted (but unacknowledged) contributions to that class make it usable, and Sun (if you are reading this), I advise you to consider acquiring that and related classes if you ever decide to add support for unsigned integers to Java.

I made the simulator's ELF loader more robust, explicitly checking EI_CLASS and EI_DATA.

The simulator application has one dependency that I really don't like. You will experience a fatal exception if you don't have Apache Derby installed. The reason I don't like that dependency is that I have given you the option to limit yourself to interactive use of FSS (i.e. without automated verification). If you don't intend to use automated verification, then you don't need Derby. But you do. So I fixed this false Derby dependency.

I suspected that there would be a problem selecting Automated Verification, deselecting it, then selecting it again. There was. That's fixed now.

I could no longer tolerate the fact that the postsimulation application always shows all results. This made it difficult to find any failing results by scrolling over tens of thousands of rows after an overnight automated verification run. So I added a feature allowing the user to select to display all results or only failing results.

Then I made a software architecture improvement by limiting which parts of the simulator application depend on the JHDL class library.

In the midst of that software architecture improvement, I prepared (in StarOffice Impress) and rehearsed a presentation on this Java project for the Java Austin Special Interest Group. Due to poor attendance and venue, however, the presentation was never delivered.

Finally on 2007-07-21, I got back into the Sputnik microprocessor and its implementation of the SPARC-V9 MULX instruction. I had been looking forward to this for quite some time.

Sputnik is currently part of the FSS application suite. To make FSS useful for its intended purpose (i.e. verification of your SPARC-V9 implementation), Sputnik will eventually have to be replaced by a virtual socket in the testbench. And the SPARC-V9 Standard Reference Model described in Requirement 1.7.2 will have to be developed. For now, all of the SPARC-V9 instruction execution capability of FSS is coming from Sputnik.

An implementation of an integer multiplier has been in place in Sputnik (e.g. FSS Version_0-006) and it is being clocked. However, Sputnik's control unit has not been babysitting the multiplier. In fact, Sputnik does not recognize MULX, regarding it as an illegal instruction. Implementing that is the next step.

On 2007-08-03, I observed that the product_valid signal out of the multiplier is asserted for the first time, so Sputnik is multiplying!

But it's not multiplying correctly at this point. It may be simple to debug this Sputnik problem using jdb, but I have to think about how you will debug your design under verification (DUV). When debugging Sputnik I will limit myself to the FSS user environment. You will (eventually) have your own DUV, described in JHDL. That DUV won't meet FSS until the testbench has a virtual socket. Even then, I have not thought through whether or not debugging with jdb will be possible.

More importantly, look at what the SRS promises.

Requirement 1.9.3: Those are interactive debugging features of the controller. They will be very useful and very time-consuming to implement.

Technically, "stop on product_valid" is not part of Requirement 1.9.3, although Requirement must be satisfied even after "stop on product_valid" is implemented. It was foolish of me to omit "stop on product_valid" from the SRS. Requirement 1.9.3 provides features to stop on a MULX instruction in assembly language, either by stepping or by breakpoint, but it does not force me to provide users with the ability to step within the MULX instruction!

In the meantime, we have Requirement 1.8.2: These are waveform features of the view. I have already started work on this. The requirement doesn't say much about this, just that the user can monitor both internal and external signals. (He/she already can.) Postsimulation tools are outside the scope of the SRS, but as long as I am within the simulator application (and specifically within the view) and making its waveform features more useful, then it is fair to say that I am working on Requirement 1.8.2.

So I've put the hardware design on hold for the moment while I go back into the software to make the waveform viewer more powerful.