Would love an exact quote from the patent file, of "The purpose of the pool of SRAM in the IO Complex--the SRAM I was referring to--is explained further along in the patent documentation." instead of trust me I've read this more than you and thus know it by heart. Put money where your mouth is and show the receipts like I did or I'm unconvinced.
Plus "You've found that the flash controller uses it too" this didn't come second, or later on. I already knew this one AND the one in the main custom chip, but wondered why people were not speculating any uses of SoC SRAM and just assumed, that one as well was known generally and speculated on by-and-large in the past. However it seems I was wrong.
I'm really not into the childish forum gauntlet throw downs, and the only reason I clarified what I meant when you assumed I was unaware of SRAM in the controller is because the discussion on the usage on SRAM in the flash controller and what it's used for and why was a few pages ago and is something I personally wrote a fair bit about, but maybe you weren't involved in the thread during it, which is fair enough. It's impossible to keep up with this place completely.
After discussing how the flash-controller uses SRAM to store a partial (and cleverly optimised and much smaller than typical) mapping table between logical and physical addresses, I then stumbled upon a different mention of SRAM in the patent in a section where it was discussing elements of the IO complex on the main SoC and outside of the flash controller. It's also referred to as "a" pool of SRAM and isn't labelled in any figures, whereas the SRAM on the controller is always referred to as "the" pool of SRAM with a reference immediately following it which indicates its location in the flash controller.
Here's where I postulated what it was being used for based on the patent and Cerny's slides:
PS5 game development had almost 2 year headstart, and we know for sure that devkits of PS5 could have such a headstart PS5 was originally a 2019 console that got delayed.
www.neogaf.com
Here's the full patent paragraph discussing elements such as the sub-CPU (co-processor) and accelerator (Kraken and other elements):
The sub-CPU 32 divides a file read request issued by the main CPU 30 into read requests for data of a given size, storing the requests in the system memory 14. Thus, in the present embodiment, hardware other than the main CPU 30 handles the major part of data access to the flash memory 20, and the read unit is reduced to a finer one immediately after issuance of a file access request. This allows for parallel access to a plurality of NAND devices, thus providing a high transfer rate. Further, affinity with processing handled by the accelerator 42 such as read data buffering to a built-in SRAM, encryption, and tampering check is enhanced in terms of data size, thus preventing disruption of processing halfway.
Emphasis mine.
The accelerator is what's described as being responsible for decompression and other tasks. It's a logical stand-in for the patent for the actual implementation that uses a Kraken hardware decompressor etc.
The SRAM on the controller is used for caching parts of the mapping table for speedy lookups of the actual physical address, and for a basic ECC check. It is always referred to as "the" SRAM and explicitly labelled.
Considering the entire point of SRAM is bandwidth and latency, there's just no way the accelerator (Kraken decompressor) is doing this over 4 lanes of PCIe and using the flash controllers pool of SRAM that it needs for its own tasks. Sharing both SRAM bandwidth
and PCIe bandwidth. It cannot be the case.
It seems as if the IO Complex SRAM is used for read buffering for the Kraken decompressor, decrytion and tampering check, which are parts of the check-in process.
Also the check in process still happens, it's just that the CPU doesn't need to do it or even be aware of it, and it's hardware offloaded by a sub-CPU (one of the co-processors) and the DMAC.
I'm too old for trying to look like some kind of obnoxious bad-ass on an internet forum. I wasn't trying to call you out or anything. It's just that you quoted me to tell me about something I already knew--wasn't really talking about--and had talked about a fair bit a few pages ago.
www.notebookcheck.com
