SPI flash chip eMMC module on Rock 5A

#1

I’ve found the reason for the flash chip eMMC module supplied with the 5A:

https://wiki.radxa.com/Rock5/install/spi

It looks like it can be removed for normal use and replaced by an eMMC module for booting an OS.

#2

Well, yes, of course it can be removed, did anyone think it can’t? This doesn’t explain, however, why the SPI is not soldered.

#3

That’s because eMMC and SPI flash share the same pin, they can’t exist at the same time.

#4

And yet they exist separately on Rock 5B…

#5

Correct.
5A is based on RK3588S, not RK3588 like 5B, and the main difference between the two SOCs is that RK3588S doesn’t have as much I/O pins.
It’s the same reason why 5A doesn’t have a fully-featured PCIe3x4 port, unlike 5B.

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