Important color changes


Hm, according to September, October, November, and December the year should start with March. What am I missing?
 
Are you sure it's not the TWL6030 or some other product? The TWL6040 appears to be for audio.

Ah, sorry, yes! It's the TWL6037 :)
That's what happens when you post it without checking the schematics...

But back to the 4GB RAM--isn't the issue that your 1.35V rail dropped out of spec by the time it reached your RAM, but was still regulated to 1.35V at the source? Even if you try to minimize IR drops, fundamentally isn't there still a discrepancy between where this rail is regulated and what voltage is at the RAM? You mentioned the PALMAS chip is responsible for regulation--does it monitor the 1.35V at the source or does it monitor the voltage at the RAM?

As far as I know, the OMAP5 is constantly being regulated by the PALMAS (via a communication line, if I'm not mistaken).
The DDR is directly connected to the OMAP5 (even the power), and I'm not sure whether that's even regulated or whether it is just set to one fixed value.
I THINK it's the latter one, as we can set the voltage via software.

The RAM just needs something between a minimum and maximum voltage and will work.

I'm curious about the margining--it seems the lower spec limit for the RAM is 1.215V based on the graphic, and we're getting down to 1.245V in simulation with the improved layout? So, that's 2.4% (30mV) of margin--is that enough margin for component/manufacturing variability and any possible discrepancies between simulation & real-world? Does the 2.4% budget in transient response (is this a DC simulation? I'm curious as to how low those 1.245V nodes go in a transient response)? Are any of these traces accessible (perhaps with minor hacking if need be?) with a multimeter for correlation to simulation (I know the memory is a FBGA package, so probing the individual nodes is unrealistic, but I was wondering if there were some other point on the 1.35V rail that could be probed for correlation)?

The simulation is pretty accurate, no worries about that.
The IBIS files and all other information from the chip manufacturers usually include such tolerances. It wouldn't help much if you simulated everything knowing it still might not work :)

Juliano and Nikolaus might be able to tell you more about all that, I'm no expert here, I'm trying to understand everything as well. :)

Lastly (sorry for all the questions!), what determined the 1.35V +/- 10% spec in the graphic? My impression is that the Pyra uses DDR3L, which I thought has a lower spec of 1.283V?

As far as I know, the tolerance limits are ON TOP of the voltages, so 1.283V +/- tolerance is the lowest voltage the RAM HAS to work.
Don't forget: We already have some CPU boards that work with 4GB RAM even though the simulated voltage drop on our current CPU board goes down to about 1.13V (AFAIR correctly)

Important to remember: The given tolerances and voltages for DDR means: They HAVE to work with that setup!
So the manufacturer has to make sure these settings work - and as they also have tolerances in production, they have to widen that margin as well, so RAM will work with less power than needed.

And: We can ADJUST the voltage. So we could easily increase the voltage to 1.36V or 1.37V if need be. But the old PCB still had a too high drop for that.
 
Hm, according to September, October, November, and December the year should start with March. What am I missing?
You are missing the fact that a certain roman was going to be emperor at the start of certain year. Because he wanted to be emperor NOW, he decreed the year started 2 MONTHS earlier.

In 45 B.C., New Year's Day is celebrated on January 1 for the first time in history as the Julian calendar takes effect. Soon after becoming Roman dictator, Julius ...
 
@FBnil thank for the info. Did he leave the Months names on purpose to confuse me or did he just not care leaving such half-baked shit behind?
 
@FBnil thank for the info. Did he leave the Months names on purpose to confuse me or did he just not care leaving such half-baked shit behind?

Apparently, the Romans claimed they used to have 10 months, but by the time the roman republic came about, they'd added january and february to bring them up to 12, and they set the months to be fixed lengths, rather than just happening when the church decided a new month had started.

None of it is Julius's fault either. Apparently, Quintilis and Sextilis were already months 7 and 8 before they got renamed to July and August. And it wasn't Julius who renamed Quintilis as July, that was Mark Anthony who did it after his death. Sextilis was renamed August during Augustus's watch though, although there was at least a referendum about it.

Julius did introduce leap years in place of an occasional 23 day month that got squeezed in between February and March that they had been using. It's only partially his fault that the priests couldn't count and put in a leap day every three years instead of every four, which only got spotted by Augustus later on.
 
It's only partially his fault that the priests couldn't count and put in a leap day every three years instead of every four, which only got spotted by Augustus later on.
It is noteworthy but less known that our Gregorian calendar has more rules to determine the existence of a leap day than "every 4 years" compared to the Julian one: Every year that starts a new century does not have a leap day, unless it is dividable by 400. The last year that was excluded from the 4-years-rule was 1900, the next one will be 2100.
 
Thanks agaon for the info. This is quite enjoyable.
So now that we're two millennia in, could we please change those Latin numeral's and their derivatives' semantics after the fact. We'd then also have to change the number of limbs the octopi get, of course. Poor octopi.
 
Surely it's easier to learn that if you see a word ending in 'ber' it means add two?

Certainly easier than relearning the last months of the year as November, December, Hendecember and Dodecember.

Edit: Actually, maybe month 11 should be undecember, not hendecember, since months come from latin not greek.
 
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OK,
wonderful news (and yes, all the best for 2018 to all of you, especially EvilDragon!).

Does this news have a chance to translate in an update on the project plan, aka shipping timelines?

my Pandora is still running strong, but nevertheless I'm eager to get my Pyra :)

peb
 
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