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nsteel 3 days ago

But they obviously knew the RAM was EoL since they already use it in the zero 2. It would be monumentally incompetent for either party to not know this so there must be a plan.

Perhaps these RAM chips are more readily available in China through some means. There are companies that will extend the lifetime of a product if you can get them the design, we've used it for niche (expensive) RAMs. Surprised that would be worth it for something at the low end. Maybe they just have a huge pile of them in China.

phire 2 days ago | parent [-]

The 512Mb RAM die actually embedded into the same RP3A0 package as the CPU (it's the exact same CPU die used in the Raspberry Pi 3). So the stock is exactly the same world wide and linked. and I'm pretty sure the RP3A0 chips are packaged outside of China and would need to be shipped in for this.

Besides, China's RAM manufacturing is reasonably new, and only makes DDR4 and LPDDR4, not the older LPDDR2 which the RP3A0 uses.

But yes, they would have known LPDDR2 was EOL. It was EOLed 6 years ago, before they even launched the zero 2 (which they only introduced because the BCM2835 chip used by the original Zero was EOL), so it's not exactly clear why they are launching the CM0 now.

What makes the most sense to me is that they are currently developing a new chip, that will be a more-or-less drop in replacement for the RP3A0. If it's drop-in, then the design work on the CM0 won't be wasted.

Which would give us some clues on what the RP4x chip is, and it's current status (close enough that they know it will arrive before they run out of RP3A0 chips for the Pi Zero 2, but far enough away to bother launching the CM0 now, as long as the supply is limited).

This RP4x chip presumably needs to have low enough power/costs to fit the Pi Zero 3 budget (so quad Cortex-A725 cores?), while also using modern memory, LPDDR4 if not LPDDR5 to push the EOL out as far as possible. Since the Raspberry Pi 3 depends on the same EOL LPDDR2 memory, this theoretical RP4x chip will probably be used for a product refresh there too (and lowering their costs, as a bonus).