Posted by Michael Posner on July 17th, 2014
By far my favorite aircraft growing up was the Harrier jump jet. Back in those days it was the only jet aircraft with vertical takeoff and landing (VTOL) capabilities. I dreamed of flying one and even owning my one. Actually I still dream of owning one. I like the idea of a helicopter as you can vertically takeoff and land meaning you have a wide range of landing zones. The problem with a helicopter is that it’s very slow in comparison to a plane so it would take you ages to get any real distance. Hence the Harrier was a perfect option for me, vertical takeoff and landing and jet speed in the air, it’s the best of both worlds.
In the land of FPGA-based prototyping there is a lot of horizontal and not much vertical, especially when it comes to daughter boards. Traditional daughter boards are flat or horizontally mounted to the system such as the HAPS DDR3 daughter board pictured below.
There is nothing wrong with a daughter board like this, in fact the above daughter board has exceptional SI characteristics and operates at very high performance. However we found that some customers ran into challenges when it came to building custom daughter boards specifically tailored to their needs. Here is a summary of some of the issues they ran into.
- Customers daughter board was quite big but it only required a couple of IO’s interfacing to the system. Often the daughter board covered up more connectors or blocked airflow and fans just because the daughter board PCB had to be large to accommodate the custom logic
- The daughter board required a big connector, but again only required a couple of IO’s. The size of the connector forced the size of the daughter board PCB to again cover things.
- Once in a while the customer actually wanted to get access to both sides of the daughter board. Sometimes this was to connect to both sides, other times to probe. They would build a long daughter board expanding out of the system to do this. It was typically mechanically unsound.
Enter the Synopsys R&D Boffins! They could have ignored this little gripe with daughter boards, lets face it, the issue is annoying but not the end of the world. But that’s not good enough for the Synopsys! So drum roll please……. for the worldwide announcement of the availability of the VERTICAL HAPS daughter board. Yes, vertical….
The new vertical daughter board addresses the issues laid out above.
- For daughter boards that use relatively few IOs, say up to 50 (HT3 connector IO count) but require more PCB real estate than a typical LAB board, building in a vertical way is excellent. Look at the picture, the board form factor is huge yet it only plugs into and utilizes one HT3 connector. It does not block any other connectors or airflow.
- Same for the problem of the big connector, a vertical board enables a HUGE connector to be used if wanted.
- Oh my, you can even access both sides of the daughter board, perfect for additional PCB access and probing.
The HAPS HT3 spec is being updated to define the new HT3 vertical daughter board and will be available to all existing HAPS-70 customers. Synopsys validated the form factor and usage and now shares it with any HAPS-70 customer that wants it.
So now we can all go vertical. Ease of use, functionally with performance, it’s like the Harrier jump jet of FPGA-based prototyping daughter boards. Someone once made fun of the upper frame on the HAPS-70 systems, now who’s laughing……