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sipeed / LicheeRV-Nano-Build

LicheeRV-Nano-Build
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How to switch board to arm mode ? #59

Open Cpasjuste opened 1 week ago

Cpasjuste commented 1 week ago

Hi,

To enable the a53 arm core, do we need to remove the "RISC-V C906 / arm A53 Select" resitor ?

Thanks.

Taumille commented 1 week ago

Hello, as far as I know yes, the switch can only be made through this resistor. There is three pins, VDD, CPU_SEL and GND, by default CPU_SEL is connected to VDD so the selected CPU is the RISC-V C906 but you can connect it to GND to use the Arm core, here is a part of the schematic

2024_11_06-14h02m45s

If you want to use the SG2002 SoC with its Arm CPU, you can buy the MilkV Duo 256M which has a "Boot Switch" pin that can easily be grounded.

Cpasjuste commented 6 days ago

Hi @Taumille,

First, thanks for the valuable information, it's hard to find some for this device.

Else I think I won't go for the soldering on those tiny pads, while I have the necessary tools I won't bother with that I guess. I may change my mind about this at any moment though. Also, I can't go for a bigger device, my goal is to test/replace the pico in my own made "micro rp2040 handheld", for fun.

Since I was not sure of the "switch" stuff, I started digging with the "riscv side", and it's fine/cool. That said, this repo is a little "chaotic", no offense. So I did start looking around and found your patches, then your GitHub and all the work you've done with this device. I must say that I'm very impressed, while there's some work left, it's very clean. Thanks for your work mate :)

I just forked your work today, hopefully I may be able to help a little (but while I'm developing "for fun" since maybe 15 years on many various stuff, Im far from your level :)).

Et vive la France :p