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  • RP2040 / Pico shared ram?

    From john larkin@3:770/3 to All on Thu Oct 3 15:32:16 2024
    Given an RP2040 CPU with two ARM processors (we call them Alice and
    Bob), how can they talk to one another?

    We hate FIFOs. Is it possible for them to share a block of the SRAM?
    It would be cool if the two programs could both declare a struct and
    both be able to access it simultaneously. We's manage the access
    details ourselves, who writes to what variables.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Brian Gregory@3:770/3 to john larkin on Tue Oct 8 03:04:10 2024
    On 03/10/2024 23:32, john larkin wrote:
    Given an RP2040 CPU with two ARM processors (we call them Alice and
    Bob), how can they talk to one another?

    We hate FIFOs. Is it possible for them to share a block of the SRAM?
    It would be cool if the two programs could both declare a struct and
    both be able to access it simultaneously. We's manage the access
    details ourselves, who writes to what variables.

    Don't they share all the RAM like any other 2 core processor would?

    --
    Brian Gregory (in England).

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Kees Nuyt@3:770/3 to void-invalid-dead-dontuse@email.inv on Tue Oct 8 13:49:04 2024
    On Tue, 8 Oct 2024 03:04:11 +0100, Brian Gregory <void-invalid-dead-dontuse@email.invalid> wrote:

    On 03/10/2024 23:32, john larkin wrote:
    Given an RP2040 CPU with two ARM processors (we call them Alice and
    Bob), how can they talk to one another?

    We hate FIFOs. Is it possible for them to share a block of the SRAM?
    It would be cool if the two programs could both declare a struct and
    both be able to access it simultaneously. We's manage the access
    details ourselves, who writes to what variables.

    Don't they share all the RAM like any other 2 core processor would?

    We don't have to guess, the chip is documented very well:

    <https://www.raspberrypi.com/products/rp2040/specifications/>

    Scroll to "Documents" - click "RP2040 datasheet"
    --
    Kees Nuyt

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)