P2 hardware design guidelines?
Peter Jakacki
Posts: 10,193
I think at this stage that I would like to produce a P2 board in both as a system and in modular form but is there any information about design considerations such as use of pins, power, chips, etc? Although I could just finalize designs that I had started before it seems that with the discussions on how memory will be interfaced and how pins might be reused etc that it would be helpful to have this information all together in one place.
One board design will be PC style in that it will have connections for USB keyboards/mice, VGA/HDMI, SD, Ethernet and possibly Wifi and SDRAM of course so that I can fully test the capabilities of the P2. Puppy module sockets will allow for a wide variety of interfaces on top of this, so this should prove to be a great development platform.
One board design will be PC style in that it will have connections for USB keyboards/mice, VGA/HDMI, SD, Ethernet and possibly Wifi and SDRAM of course so that I can fully test the capabilities of the P2. Puppy module sockets will allow for a wide variety of interfaces on top of this, so this should prove to be a great development platform.
Comments
What is the recommended crystal frequency and loading etc?
Do we have any idea about current requirements for the core?
What schemes or variations do we have for booting?
I'm ready to push out a P2 SBC design and I'd like to have it ready for P2 when I'm back in October. I'll mainly use this for development a bit like the iConsole I designed years ago for the P1 but since it's designed to fit into an enclosure and even be self-contained with a touchscreen then it could be used for some applications as is.
P2 SBC features:
any other GPIO?
5-28V would be nicer, then the expanding Phone charger standard can be used.
No mention of SPI flash (so the system does not have to use a SD card) - SD cards are nicely portable, but it is also a set pf physical contacts, which is just a failure point to some apps.
Or was the boot flash assumed to be large ?
[I've forgotten how large a Boot flash the Prop 2 tolerates ?]
The boot flash can be a 64Mbit device if need be so there was no need to mention every little detail, just some desired features. Normally I allow for an SPI Flash chip whenever I have any kind of SD card, adding multiple footprints for various options is easy. Even if there are no I/O free the SPI Flash can use the lines that would normally be used for the SD. In the P2 however we have plenty of I/O (until we use it all up) and so the spare I/O will go out to the Puppy module sockets and to a general I/O expansion header with SPI Flash already a part of the boot memory. If I need a prototyping area then I prefer to do that on my prototyping Puppy modules so that they can be changed easily. A double module can be used in place of the standard single unit otherwise a board can be plugged into the expansion header.