Product Idea: USB Flash Drives

[dsimic]

Yeah, it was just the first example I found on a little search. The bottleneck would likely be the BL602 SPI bus speeds to be honest. I haven't found any good data on it yet.

Well, you're right and unfortunately there's some bad news.   Here's a quotation from the BL602 feature list, found on page 6 of the BL602 datasheet:

One SPI master/slave with max clock 40Mbps

Consequently, even with the quad-SPI flash connected to a completely separate controller and interface (according to the block diagram on page 9 of the BL602 datasheet), anything going through the BL602's SPI bus would be limited to 40 Mbit/s, which includes the required USB interface.  Quite frankly, a storage device that provides about 4 MB/s at its USB interface would be rather pointless.

Strictly in theory, another approach might be to use the BL602's SDIO 2.0 interface to connect a USB interface.  It should provide reasonable speeds, but I really don't think that an appropriate SDIO-to-USB bridge device exists.  There are USB devices that provide an SDIO interface, but there's pretty much no reason for an SDIO device that provides a USB interface to exist.

Unfortunately, I'm no longer optimistic about using the BL602 for the new storaga device, it would be unusably slow.   Quite frankly, everything says that we should look for a better microcontroller choice for the new storage device.

As a side note, more information about the software side of the BL602's SPI interface is available here.

Where is it hiding? https://wiki.pine64.org/images/a/af/Pine...-small.jpg
I see the BL602 and clock crystal on the upper board, then some USB chip and power modulation on the lower board.
On the Wiki, when it talks about 2MB embedded flash, I think it means inside the BL602 itself? https://wiki.pine64.org/wiki/Nutcracker

You're right, according to the wiki page and the released schematic, the BL602 boards released by Pine64 provide 2 MB of embedded flash.   Furthermore, the IC on the board picture is labeled BL602L20, which additionally confirms that it contains 16 Mbit (2 MB) of embedded flash (see my comment below).

Excuse me if I misunderstood your question, but I think it is on the IC itself
https://github.com/pine64/bl602-docs/blo...1.6_en.pdf  (PAGE 6)

So on page 7 you have "XIP QSPI/SPI Flash with hardware decryption support" and "Embedded Flash (Optional)" - it's not obvious to me that the embedded flash operates through the XIP SPI section. I looked through the whole document, but couldn't see anything that for sure showed that the optional flash is on the XIP SPI bus.

If it was on the XIP SPI bus, that would raise different questions, like how it would boot up when there are up to four devices? Which one does it enable before it's loaded it's first byte of code?

According to the table on page 11 of the BL602 datasheet, the memory map includes space for 16 MB of XIP (execute in place) flash memory.  It is unclear whether those 16 MB present the liimit for the size of the external flash?  Probably not, but the XIP feature should require the flash to be part of the memory map?  Maybe only one part ("XIP window") of the flash is mapped at once?  Also, the memory map says nothing specific about the embedded flash.

Another interesting piece of information is available on page 29 of the BL602 datasheet.  When it comes to the embedded flash, there seem to be four variants of the BL602: no embedded flash, 8 Mbit (1 MB), 16 Mbit (2 MB) and 32 Mbit (4 MB) of embedded flash.

Ps. For some reason, the forum inserts newlines every time and I cant delete them, sorry

You can edit the source of your posts, by clicking on the rightmost button on the editor toolbar, and remove any erroneous newlines.  That's also how I write posts most of the time.