Quartus II v7.2 changes to Signaltap

[Altera_Forum]

Hello, 

 among other changes, with v7.2 the Signaltap embedded logic analyzer is said to be improved. Before I could evaluate any improvements, I was aware of some changes, that appear to me as unexpected step back. When importing a stp file from v7.1 that occupied 1195 LEs to v7.2, it was blown-up to 7621 LEs (it utilized segmentedx1 acquisition). Restricting the trigger to circular only, still 1477 LEs were needed. This means practically, that the segmented acquisition mode can't be used any more without a huge resource overhead. E. g., the said 1k LE stp example was used in an EP2C8 design, guess how many LEs are remaining here! Particularly the x1 segmented mode seems interesting to me as replacement for an otherwise missing clock qualifier with signaltap. (Fortunately THE competitor also has no clock qualifier with ILA core).  At first look, it seems that v7.2 must not be used for some (resource critical) designs. Or did I overlook something important?  Additionally, I'm missing a "save as v5 Signaltap file" option. For stp files, that don't utilize new options, the only difference is in the version number.  Regards,  Frank

[Altera_Forum]

It is true that 7.2 uses more resources than 7.1. The increased resource usage is used for handling the buffer management scheme in 7.2. Changing the segmented buffer has the greatest impact on resource utilization as compared to any of the other setting. Though, performance of the SignalTap core is better in 7.2 as compared to 7.1. - SignalTap in 7.2 will be able to maintain a higher fmax.  

 One of the new features that was introduced is the trigger flow definition. You might get the debugging visibility that you're looking for by creating larger segments in the acquisition space, creating a handful of trigger conditions, and use the trigger flow definition to define how each acquisition segment should fill. This maybe a viable alternative to using a clock qualifier.   Another thing to note is that an STP file created in 7.2 can be used in 7.1. When migrating back, most of the setup options will remain intact. When opening up the file in the older release, SignalTap will prompt you to "upgrade" the file.

[Altera_Forum]

Hello, 

 I think, that the new Signaltap version basically offers improvements, although I wasn't able yet to evaluate them in detail. But it's also true, that the segmented acquisition mode can't be used any more if LE resources are low. For the particular design, I'll stay with V7.1. Usually, I keep several previous Quartus versions in my development enviroment cause synthesis results sometimes are different.    --- Quote Start ---  Another thing to note is that an STP file created in 7.2 can be used in 7.1. When migrating back, most of the setup options will remain intact. When opening up the file in the older release, SignalTap will prompt you to "upgrade" the file.  --- Quote End ---    I also think, this should be possible but don't see yet, how to achieve it. With V7.1 I just get an error message: "...You must use a newer version of the Quartus II software to open this file".  Best Regards,  Frank