possible to design own version of pi?

[lilzz]

if i use DDR3 memory instead of DDR2 or vice versa that means I need to program the memory registers. But I do not have source of boot code.bin to tweak those memory register timings so I guess its not possible then?

[Ravenous]

Depends. Which memory are you intending to use?

[klricks]

if i use DDR3 memory instead of DDR2 or vice versa that means I need to program the memory registers. But I do not have source of boot code.bin to tweak those memory register timings so I guess its not possible then?

The memory is PoP stacked on top of the SOC:
http://en.wikipedia.org/wiki/Package_on_package

It's not possible to physically modify the memory even if you did have access to the programming registers.

[lilzz]

if i use DDR3 memory instead of DDR2 or vice versa that means I need to program the memory registers. But I do not have source of boot code.bin to tweak those memory register timings so I guess its not possible then?

The memory is PoP stacked on top of the SOC:
http://en.wikipedia.org/wiki/Package_on_package

It's not possible to physically modify the memory even if you did have access to the programming registers.

where to buy that SOC from distributor? I wants build a very simplified Pi without some many connectors.

[RaTTuS]

http://www.raspberrypi.org/forums/viewforum.php?f=98
is going to be the best you can do.
unless you are ordering millions you will not get access to the SOC

[lilzz]

http://www.raspberrypi.org/forums/viewforum.php?f=98
is going to be the best you can do.
unless you are ordering millions you will not get access to the SOC

is there a computer module that use the same SOC as the Pi?

[Ravenous]

Are you going to try to desolder one from an existing device?

[plugwash]

The Pi's firmware is licensed for use only on raspberry pi products not on other devices with the same SoC. Also broadcom don't like dealing with little guys (the raspberry pi foundation got an exception because they were insiders).

Last time someone tried to build a variant of the Pi they managed to get some initial parts out of broadcom but later got snubbed. It's not entirely clear why (the two main possibilities I can think of are either the licensing issue mentioned above or that they just weren't prepared to order enough).

So sadly if you want to build your own board with a SoC directly on it you will have to look elsewhere. The TI based beaglebone black is probablly a good starting point for a device at a comparable level* that can be used as a basis for your own designs.

Also note that designing and building boards at this level is nontrivial, you will be dealing with multilayer PCBs, BGAs, high speed signals, sensitive power etc. I would expect to be spending the best part of a thousand pounds per iteration on fabrication and assembly costs alone.

The raspberry pi compute module (same SoC as the Pi) may be an option for you, It's sodimm sized so a fair bit smaller than a regular Pi (and a heck of a lot smaller than a regular Pi with connectors sticking out) but still non-negligable size. Building a board with a socket for the compute module is probablly towards the upper end of hobbyist level PCB work.

As for ram types if it was possible to use DDR3 with the raspberry pi's SoC I imagine the foundation would have done it. IIRC DDR3 is quite a bit cheaper than LPDDR2.

* Yes I know it's weaker in some areas and stronger in others but overall I consider it to be at a compable level.

[fruitoftheloom]

This is the post pointing to the other Device which was mentioned above:
http://www.raspberrypi.org/forums/viewt ... 62&t=85645

Anther use of the BCM2835 is in some models of Roku
http://en.wikipedia.org/wiki/Roku

[jamesh]

http://www.raspberrypi.org/forums/viewforum.php?f=98
is going to be the best you can do.
unless you are ordering millions you will not get access to the SOC

is there a computer module that use the same SOC as the Pi?

The Raspberry Pi compute module. Just has the SoC, RAM and eMMC, no other stuff to get in the way. Sounds like that is what you need.