Rev C ordered!

Rev C of titan has been released on github, and I ordered the PCB prototypes tonight.

I'm working on an inventory of the components that I have before I order new parts for the build. Thanks to Kevin for a quick review of the PCB.

Figure 1. Rev C of Titan

A different build

Today a helped a friend, Nick Huskinson, build a PCB board for his senior design project. The board implements a quad ADC using the Linear Tech LTC2170. Since Titan isn't ready yet, Nick designed this board for the Lattice ECP5 development card. Hopefully rev B will have an interface for Titan.

Figure 1. Nick's ADC Board (Ready for Relow).

Figure 2. Nick's ADC Board (After Reflow).

Rev C almost ready!

I've (finally) completed my changes for rev C of Titan. The token is officially passed to Kevin for review. I'll post more about the changes on this rev soon. For now, enjoy:

Figure 1. Candidate Rev C.

DDR3 re-check

I decided to double check the DDR3 routing before finishing rev C of Titan, and I found a few length tuning issues to correct. The updates are committed on github: https://github.com/jsloan256/titan/tree/Rev-C.

Figure 1. Superfluous Picture of Titan's Updated DDR3 Routing.

Expansion interface: looking for problems

Before I dive into final tuning I decided to look for any routing issues with the expansion interface. Figures 1-6 show the issues that I found.  I'm going to shift the routing around a bit to try to limit long runs where traces are run closely in parallel.

Figure 1. Tight Routing Between P3 and P5.

Figure 2. Long Parallel Routing.

Figure 3. Too Tight Length Loop.

Figure 4. Too Tight Length Loop.

Figure 5. Long Parallel Routing.

Figure 6. Too Tight Length Loop and Long Parallel Routing.

Expansion interface: rough tuning complete

I finally found some cycles to work on Titan today. I was able to complete the rough tuning of the expansion interface. I still need to tune the length a bit more, match the differential pairs, and I have a bit gold plating left (by gold plating I mean adding a little bit of beautification polish). The good news is that I had enough room to match the expansion trace lengths; It was not an easy task with the minimum and maximum trace lengths differing by as much as 2.5 inches.

Figure 1. Rough Tuning Complete.

Motivation

I let myself get behind on the layout because we didn't know when we would get more ECP5s. Guess what showed up yesterday? Looks like I need to get busy!

Figure 1. The Item.