2011/5/31 Steve Wiseman <email@example.com>:
> Some responses:
> Hector - that supplier of Micron parts - have you used them / got
> prices? That looks suspiciously like the full list of Micron orderable
> parts. We definitely do need to sort out which shape LPDDR chips we
> want / can get, and quite soon. If they're a real vendor, that's
No, I have not used them, it looks like a Micron reseller, I am
contacting them to see if we can get a quote.
Just for the record LPDDR manufacturers I have only found elpida,
micron and samsung <
http://www.samsung.com/global/business/semiconductor/products/dram/Products_MobileSDRAM.html > Another useful link, < http://processors.wiki.ti.com/index.php/LPDDR >, hints me that we might be ok doing 2x16 or 1x32. I'll post something if I find out more on this topic.
> (An LPDDR point of note - I've got a pile of Beagle-xMs that have -166
> memory (in PoP package, so tiny short buses). They don't work at all
> well at 200MHz. There's evidently not a lot of slack in this system.
> This may, or may not, bode ill for stacking two multi-die 4Gbit x32
> chips on B4).
Pandaboard using OMAP4 is using elpida chips and first revisions of
pandaboard had to be clocked at 100MHz, they had lot of trouble with
Elpida PoP chips too.
> Hector - STM32 H107 Yeah, can't see why not. How much current is it
> taking in real sleepy-modes?
This is just theoretical I have not measured it.
"The STM32 is fabbed using STMicroelectronics' 0.18µ embedded flash
technology process. The STM32 seems a perfect match for this process,
as it draws a mere 36mA at 72MHz - that's at full run mode with
everything on. According to ST, competing Cortex designs have managed
100mA while running at much less than 72MHz.
In Sleep Mode, the STM32 has the CPU shut down with all peripherals
running. The current draw in this mode is 2mA.
Stop mode has the CPU and all peripherals shut down (clocks to
peripherals are gated off) with only the real-time clock (RTC) and
data RAM powered up. This pulls the current draw down to 14µA. In this
mode, the CPU required 7µsec to wake up
Standby is the STM32's most miserly power setting. Everything is
turned off except the RTC and a few bytes of backup RAM (20 bytes for
the original family, 84 bytes for today's new devices). This drags the
current draw down to a scant 2µA to 3.4µA. The sleeping CPU can wake
up in 40µsec from standby."