deralbert
Posts: 6
Joined: Wed Nov 06, 2019 4:04 pm

Are there BCM2711 ARM Peripherals?

Wed Nov 06, 2019 4:47 pm

Hello everyone,

my question is the following: Where can I find the specifications for Raspberry Pi 4 model B (BCM2711 ARM Peripherals)? A specification that is as informative as the one for BCM2835?

I am particularly interested in the information about the GPIO on the Raspberry Pie 4 model B. I would be happy with something like that screen below. I also know that there is the Raspberry Pi 4 model B's Datasheet, but this datasheet is (very?..) preliminary and lacks the addresses of the general purpouse registers associated with GPIO's. I need this addresses in order to experiment with bare metal. But it would be good if I also had the complete documentation for all peripherals, not just for GPIO's.

Thank you for your answers. Best regards,

deralbert
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Excerpt from the BCM2835 ARM Peripherals
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trejan
Posts: 4449
Joined: Tue Jul 02, 2019 2:28 pm

Re: Are there BCM2711 ARM Peripherals?

Wed Nov 06, 2019 6:27 pm

The BCM2711 peripheral documentation hasn't been released yet. It is coming soon etc...

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joan
Posts: 15940
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Are there BCM2711 ARM Peripherals?

Wed Nov 06, 2019 6:39 pm

The existing peripheral document seems to be correct for the GPIO with one known exception - the pull-ups and pull-downs are controlled differently and may be read as well as written.

The bare metal forum people will know the correct bare metal address.

deralbert
Posts: 6
Joined: Wed Nov 06, 2019 4:04 pm

Re: Are there BCM2711 ARM Peripherals?

Wed Nov 06, 2019 7:20 pm

joan wrote:
Wed Nov 06, 2019 6:39 pm
The existing peripheral document seems to be correct for the GPIO with one known exception - the pull-ups and pull-downs are controlled differently and may be read as well as written.

The bare metal forum people will know the correct bare metal address.
So I can then use the addresses from BCM2835? Or should I rather ask in bare metal forum for necessary address?

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joan
Posts: 15940
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Are there BCM2711 ARM Peripherals?

Wed Nov 06, 2019 7:46 pm

The register offsets and the GPIO peripheral offset from the peripheral's base address is unchanged (apart from the pull registers). The peripheral base address is different for the BCM2711.

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rpdom
Posts: 20022
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Are there BCM2711 ARM Peripherals?

Thu Nov 07, 2019 6:49 am

Of course if it just the basic GPIO functions that you need you can access those via /dev/gpiomem. The base address isn't needed, but as mentioned earlier the majority of the offsets are the same for all models of Pi.
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