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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 7:29 am

ktb wrote:
metalj wrote:I forfeit. The closest thing I could find was the reason other clones may not compatible which is definitely not the same.
FWIW, I do seem to recall someone knowledgeable making a very good case for what you claim. I don't think it was Eben, but they might have mentioned his name or said they based that idea on information from Eben. I don't think it really matters.
Logically it would make sense. If a new super Pi 3 had enough resource to emulate old Pi then it could break free of back-compatibility shackles without burning too many bridges.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 7:54 am

adlambert wrote: Logically it would make sense. If a new super Pi 3 had enough resource to emulate old Pi then it could break free of back-compatibility shackles without burning too many bridges.
Emulating the Btoadcom SOC on another SOC? This is ridiculous. All drivers and software accessing the SOC directly would have to be replaced / rewritten.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 8:37 am

mikronauts wrote:That's what I meant by swapping out the peripheral... I just did not state "in the SOC", I assumed it :)
W. H. Heydt wrote:
mikronauts wrote:Swapping out the USB 2.0 peripheral with a USB 3.0 peripheral would cover a multitude of sins...
It would still be limited by the USB 2.0 bus on the SoC. What would be needed (to meet your criterion) would be changing the SoC interface to USB 3.0, even if the LAN chip still only provided USB 2.0, since that would increase the aggregate data rate into (and out of) the SoC.
Just checked up with people who know this stuff - cost of moving an SoC to USB3.0 would be v. expensive, in the multi $100k's, in addition to whatever else you are doing to the chip.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 8:50 am

jamesh wrote:
Just checked up with people who know this stuff - cost of moving an SoC to USB3.0 would be v. expensive, in the multi $100k's, in addition to whatever else you are doing to the chip.
How much did it cost to get the BCM2836 done? Getting it to run with the first batch of silicon along with the conservative changes in the design must have kept costs relatively low.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 8:56 am

bstrobl wrote:
jamesh wrote:
Just checked up with people who know this stuff - cost of moving an SoC to USB3.0 would be v. expensive, in the multi $100k's, in addition to whatever else you are doing to the chip.
How much did it cost to get the BCM2836 done? Getting it to run with the first batch of silicon along with the conservative changes in the design must have kept costs relatively low.
Well, the actual figures are clearly Brcm confidential, but ballpark figures should give some idea. It does depend on the particular licence a company has with ARM. Brcm have an ARM A7 licence so they wouldn't need to buy another one (that's going to be a couple $M at least), so that just leaves dev costs and mask, so $1.5M to $2M. A company without an ARM licence for A7's would be in the region of $3M-$4M. Note, this is just to adapt an existing chip.

Chip industry is an expensive place to play.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 8:58 am

and broadcom being one of the world biggest gig Ethernet switch manufacturers , one would of thought that they could of just slapped one anyway ;) :lol: :roll:
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 9:07 am

jamesh wrote:
Well, the actual figures are clearly Brcm confidential, but ballpark figures should give some idea. It does depend on the particular licence a company has with ARM. Brcm have an ARM A7 licence so they wouldn't need to buy another one (that's going to be a couple $M at least), so that just leaves dev costs and mask, so $1.5M to $2M. A company without an ARM licence for A7's would be in the region of $3M-$4M. Note, this is just to adapt an existing chip.

Chip industry is an expensive place to play.
Thanks for the info! Is it possible for you to give us a floorplan of the bcm2835 and bcm2836?
I am really curious about the design of the chips and how the layout has changed between them.
I'd rather not have to get some fuming nitric acid and start decapping and most likely delayering these things.
(I assume there is a power grid on top so that will make things a lot more difficult if not impossible without a ton of specialised equipment).

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 9:10 am

bstrobl wrote:
jamesh wrote:
Well, the actual figures are clearly Brcm confidential, but ballpark figures should give some idea. It does depend on the particular licence a company has with ARM. Brcm have an ARM A7 licence so they wouldn't need to buy another one (that's going to be a couple $M at least), so that just leaves dev costs and mask, so $1.5M to $2M. A company without an ARM licence for A7's would be in the region of $3M-$4M. Note, this is just to adapt an existing chip.

Chip industry is an expensive place to play.
Thanks for the info! Is it possible for you to give us a floorplan of the bcm2835 and bcm2836?
I am really curious about the design of the chips and how the layout has changed between them.
I'd rather not have to get some fuming nitric acid and start decapping and most likely delayering these things.
(I assume there is a power grid on top so that will make things a lot more difficult if not impossible without a ton of specialised equipment).
Nope to floor plans. As to the change, apart from some bug fixing, it's simply the removal of the Armv11 and replacing it with 4xA7's with a consequent increase in die size. The GPU was untouched AFAIK.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 9:23 am

jamesh wrote:
Nope to floor plans. As to the change, apart from some bug fixing, it's simply the removal of the Armv11 and replacing it with 4xA7's with a consequent increase in die size. The GPU was untouched AFAIK.
Where can I get a list of these bugs that have been fixed?
And one last question, how does the BCM2836 manage to address an additional 512MB of RAM?
Was it a limitation in pins or a limitation of the PoP that prevented the BCM2835 from addressing that additional memory?

Thansk for the answers so far!

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 9:36 am

gkreidl wrote:
adlambert wrote: Logically it would make sense. If a new super Pi 3 had enough resource to emulate old Pi then it could break free of back-compatibility shackles without burning too many bridges.
Emulating the Btoadcom SOC on another SOC? This is ridiculous. All drivers and software accessing the SOC directly would have to be replaced / rewritten.
Don't emulate the Broadcom SoC, replace it. Use the Intel Edison... x86 compatible, blue tooth and wifi built in; wonderful SoC !
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 9:39 am

bstrobl wrote:
jamesh wrote:
Nope to floor plans. As to the change, apart from some bug fixing, it's simply the removal of the Armv11 and replacing it with 4xA7's with a consequent increase in die size. The GPU was untouched AFAIK.
Where can I get a list of these bugs that have been fixed?
And one last question, how does the BCM2836 manage to address an additional 512MB of RAM?
Was it a limitation in pins or a limitation of the PoP that prevented the BCM2835 from addressing that additional memory?

Thansk for the answers so far!
The RPi has always been able to address 1GB, unfortunately no one manufacturs 1GB PoP for the BCM2835.

With the change to BCM2836 a "standard" 1GB Memory Chip could be used.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 10:05 am

plugwash wrote:
fruitoftheloom wrote: The RPi has always been able to address 1GB, unfortunately no one manufacturs 1GB PoP for the BCM2835.

With the change to BCM2836 a "standard" 1GB Memory Chip could be used.
This is not correct, the Pi2 still uses a PoP style memory chip even though it's not mounted in PoP

The RPF managed to convince a memory manufacturer to make a multi-die package that was 1GB and suitable for the interface on the 2835. Unfortunately when they tried it they ran into a bug in the memory controller. So they had to put it's introduction on-hold until they could fix the issue in the 2836.
Last edited by bstrobl on Fri May 29, 2015 11:58 am, edited 1 time in total.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 10:07 am

metalj wrote:I'm pretty sure Eben said the next raspberry pi soc will not be backwards compatible. That's what I was referring to. My point was I'm staying positive. I am chill.
It should be fairly obviously to people who know about the spec of the BCM2835 and 2836 that for the Pi platform to move forward the next SoC must break some backwards compatibility. The next SoC will, at the very least, require a new memory interface since the current one is maxed out at 1GB. I'm sure it will have at least 4 ARM cores. Beyond that is anyone's guess.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 10:09 am

jamesh wrote:
bstrobl wrote:
jamesh wrote:
Well, the actual figures are clearly Brcm confidential, but ballpark figures should give some idea. It does depend on the particular licence a company has with ARM. Brcm have an ARM A7 licence so they wouldn't need to buy another one (that's going to be a couple $M at least), so that just leaves dev costs and mask, so $1.5M to $2M. A company without an ARM licence for A7's would be in the region of $3M-$4M. Note, this is just to adapt an existing chip.

Chip industry is an expensive place to play.
Thanks for the info! Is it possible for you to give us a floorplan of the bcm2835 and bcm2836?
I am really curious about the design of the chips and how the layout has changed between them.
I'd rather not have to get some fuming nitric acid and start decapping and most likely delayering these things.
(I assume there is a power grid on top so that will make things a lot more difficult if not impossible without a ton of specialised equipment).
Nope to floor plans. As to the change, apart from some bug fixing, it's simply the removal of the Armv11 and replacing it with 4xA7's with a consequent increase in die size. The GPU was untouched AFAIK.
The cache was also boosted to make better use of the faster and more numerous ARM cores.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 10:40 am

andrum99 wrote:
jamesh wrote:
bstrobl wrote: Thanks for the info! Is it possible for you to give us a floorplan of the bcm2835 and bcm2836?
I am really curious about the design of the chips and how the layout has changed between them.
I'd rather not have to get some fuming nitric acid and start decapping and most likely delayering these things.
(I assume there is a power grid on top so that will make things a lot more difficult if not impossible without a ton of specialised equipment).
Nope to floor plans. As to the change, apart from some bug fixing, it's simply the removal of the Armv11 and replacing it with 4xA7's with a consequent increase in die size. The GPU was untouched AFAIK.
The cache was also boosted to make better use of the faster and more numerous ARM cores.
Indeed, forgot about that. So each core now has its own cache, which means the VC cache is now used by only the VC itself.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 10:41 am

bstrobl wrote:
jamesh wrote:
Nope to floor plans. As to the change, apart from some bug fixing, it's simply the removal of the Armv11 and replacing it with 4xA7's with a consequent increase in die size. The GPU was untouched AFAIK.
Where can I get a list of these bugs that have been fixed?
And one last question, how does the BCM2836 manage to address an additional 512MB of RAM?
Was it a limitation in pins or a limitation of the PoP that prevented the BCM2835 from addressing that additional memory?

Thanks for the answers so far!
No bug list I'm afraid. There were very few though IIRCm and all ARM or memory related. I believe GPU was untouched.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 11:40 am

fruitoftheloom wrote: The RPi has always been able to address 1GB, unfortunately no one manufacturs 1GB PoP for the BCM2835.

With the change to BCM2836 a "standard" 1GB Memory Chip could be used.
This is not correct, the Pi2 still uses a PoP style memory chip even though it's not mounted in PoP

The RPF managed to convince a memory manufacturer to make a multi-die package that was 1GB and suitable for the interface on the 2835. Unfortunately when they tried it they ran into a bug in the memory controller. So they had to put it's introduction on-hold until they could fix the issue in the 2836.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 11:57 am

plugwash wrote:
fruitoftheloom wrote: The RPi has always been able to address 1GB, unfortunately no one manufacturs 1GB PoP for the BCM2835.

With the change to BCM2836 a "standard" 1GB Memory Chip could be used.
This is not correct, the Pi2 still uses a PoP style memory chip even though it's not mounted in PoP

The RPF managed to convince a memory manufacturer to make a multi-die package that was 1GB and suitable for the interface on the 2835. Unfortunately when they tried it they ran into a bug in the memory controller. So they had to put it's introduction on-hold until they could fix the issue in the 2836.
Thanks!

So the changes boil down to:
-Memory controller bug fixed
-ARMv6 removed and a Cortex A7 cluster with 4 cores and cache added
-Some form of USB timer added
-Changes to ROM to allow the VPU of the VC4 to start the first A7 core with Linux starting the remaining cores
-Periphereal Addresses changed
-Bug fixes :D

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 12:00 pm

plugwash wrote:
fruitoftheloom wrote: The RPi has always been able to address 1GB, unfortunately no one manufacturs 1GB PoP for the BCM2835.

With the change to BCM2836 a "standard" 1GB Memory Chip could be used.
This is not correct, the Pi2 still uses a PoP style memory chip even though it's not mounted in PoP

The RPF managed to convince a memory manufacturer to make a multi-die package that was 1GB and suitable for the interface on the 2835. Unfortunately when they tried it they ran into a bug in the memory controller. So they had to put it's introduction on-hold until they could fix the issue in the 2836.
First I have heard of this, despite repeatedly being informed a 1GB PoP would not happen
as no manufacturer would invest money, asummed that it was a differing memory package

Another case of forum response not being confirmed or disputed by RPF :roll:
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 12:51 pm

fruitoftheloom wrote:
plugwash wrote:
fruitoftheloom wrote: The RPi has always been able to address 1GB, unfortunately no one manufacturs 1GB PoP for the BCM2835.

With the change to BCM2836 a "standard" 1GB Memory Chip could be used.
This is not correct, the Pi2 still uses a PoP style memory chip even though it's not mounted in PoP

The RPF managed to convince a memory manufacturer to make a multi-die package that was 1GB and suitable for the interface on the 2835. Unfortunately when they tried it they ran into a bug in the memory controller. So they had to put it's introduction on-hold until they could fix the issue in the 2836.
First I have heard of this, despite repeatedly being informed a 1GB PoP would not happen
as no manufacturer would invest money, asummed that it was a differing memory package

Another case of forum response not being confirmed or disputed by RPF :roll:
In the P2 case, the PoP memory doesn't have to physically match the size of the 2836 die because its not mounted on top. So the range of devices is bigger. There was a bug in the controller, but IIRC that limited the type of RAM that could be used, not the size. And no-one made RAM that worked. IIRC of course.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 7:27 pm

Is this still the thread about Avago buys Broadcom? The deal seems to be perfect. So it's not an rumour anymore. Or is it about chip specifications? I'm realy interested in the impact of this deal for the future of the Raspberry Pi, if there is any. (I mean impact, not the future ;) ) So can you tell everything about that? I mean, assuming that Avago kills the BCM chips or any similar scenario, is this the end for Raspberry Pi 1 and 2, or is there any backup scenario?
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 8:48 pm

It is not a done deal yet.

Think: Comcast, Time-Warner.
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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 9:04 pm

Hiswif wrote:Is this still the thread about Avago buys Broadcom? The deal seems to be perfect. So it's not an rumour anymore. Or is it about chip specifications? I'm realy interested in the impact of this deal for the future of the Raspberry Pi, if there is any. (I mean impact, not the future ;) ) So can you tell everything about that? I mean, assuming that Avago kills the BCM chips or any similar scenario, is this the end for Raspberry Pi 1 and 2, or is there any backup scenario?
The Raspberry Pi foundation most likely has a contract with Broadcom guaranteeing a supply of chips as long as a certain amount is bought by the foundation in regular intervals.
By law this will most likely have to be taken over by Avago.
Regardless, I doubt Avago/Broadcom will go back on that agreement since they will most likely want to cover the costs of R&D on both chips. Producing additional units won't cost them much anyway.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 11:35 pm

bstrobl wrote:
Hiswif wrote:Is this still the thread about Avago buys Broadcom? The deal seems to be perfect. So it's not an rumour anymore. Or is it about chip specifications? I'm realy interested in the impact of this deal for the future of the Raspberry Pi, if there is any. (I mean impact, not the future ;) ) So can you tell everything about that? I mean, assuming that Avago kills the BCM chips or any similar scenario, is this the end for Raspberry Pi 1 and 2, or is there any backup scenario?
The Raspberry Pi foundation most likely has a contract with Broadcom guaranteeing a supply of chips as long as a certain amount is bought by the foundation in regular intervals.
By law this will most likely have to be taken over by Avago.
Regardless, I doubt Avago/Broadcom will go back on that agreement since they will most likely want to cover the costs of R&D on both chips. Producing additional units won't cost them much anyway.
A couple of things that I've gleaned from various articles are worth noting...
--The combined company is going to be named "Broadcom, Ltd."
--Former Broadcom stockholders will wind up owning 32% of the new company.

This suggests that the deal is, in some respects, more like a merger of approximate equals than a takeover by one company of another.

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Re: Quote without comment... [Avagos / Broadcom takeover rum

Fri May 29, 2015 11:39 pm

MarkHaysHarris777 wrote:
gkreidl wrote:
adlambert wrote: Logically it would make sense. If a new super Pi 3 had enough resource to emulate old Pi then it could break free of back-compatibility shackles without burning too many bridges.
Emulating the Btoadcom SOC on another SOC? This is ridiculous. All drivers and software accessing the SOC directly would have to be replaced / rewritten.
Don't emulate the Broadcom SoC, replace it. Use the Intel Edison... x86 compatible, blue tooth and wifi built in; wonderful SoC !
Sure...as soon as Intel succeeds in making money selling an SBC with an x86 chip that (a) costs $35 and (b) runs on less than 2-5W. Pardon me if I don't hold my breath waiting.

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