General discussion • Re: What is the difference between Raspberry Pi and a CPU-based computer?

I am a newbie with some knowledge of MCUs like Arduino stuff. As far as I know, Raspberry Pi is quite similar to an MCU only that it's much quicker and it has separate flash and RAM.

The other really big difference between a "SoC" like the one on the Pi and a microcontroller is that it has privilage levels and a MMU. This is what allows the operating system to isolate processes from each other.

PC processors have varied over the years. It used to be that very little was integrated with the processor, almost all IO was provided by support chips. Even the memory controller was often seperate.

In recent years though, more has moved on-chip, You now have memory and PCIe controllers integrated into the CPU. AMD even has USB ports and the BIOS eeprom connected directly to the CPU. The AMD EPIC processors are often used without a "chipset" at all. The desktop motherboard always seem to ship with one but it's not clear if they actually need it, all the most critical IO is on the CPU.

1.I think those GIPO connectors are connected directly to pins of the SoC of the Raspberry Pi dev board, just like GPIO pins connect to MCU on any Arduino dev board. Am I right?

On the Pi 1 to Pi 4 yes.

The Pi 5 moves the GPIO pins to a seperate IO chip.

2.Why I don't see these GPIO pins on any of the motherboards of a desktop computer?

Because the IBM PC was designed for buisinesses rather than tinkerers and this has remained the Ethos of the PC industry ever since.

Is it possible to connect a pin to the CPU directly and write a program to control the output voltage so that it can control an LED?

Maybe, unfortunately the full datasheets of processors are hard to come by.

3.Is the brain of the phone more like Raspberry Pi than a CPU-based computer?

Yes.

Statistics: Posted by plugwash — Tue Apr 16, 2024 11:05 am

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