STM32H7xx_inter-core_data_share

Description

This is a library used to share data back and forth between the two cores of the STM32H7xx. It is designed to be simple, without requiring low-level knowledge, and provide lock safety for reading and writing. Besides, it is easy to understand and it uses standard C libraries.

Instructions

General

1. Include the files cores_communication.c and cores_communication.h in both core projects or in a common folder.
2. In one of the cores the function core_share_init() must be called (preferably the main core). It can be called at the beginning of the main function. And it has to be called only once.
3. In the M7 core, call get_from_m4(...) to read from the M4 core or put_to_m4(...) to send data to it.
4. In the M4 core, call get_from_m7(...) to read from the M7 core or put_to_m7(...) to send data to it.
5. You can use the function int m4_has_data(void) in the M7 core to verify whether the M4 sent data.
6. You can use the function int m7_has_data(void) in the M4 core to verify whether the M7 sent data.
7. Add the following in the linker script of each core:

RAM_D3_SIZE = 64K;

/* Memories definition */
MEMORY
{
    ...
    RAM_D3 (xrw)   : ORIGIN = 0x38000000, LENGTH = RAM_D3_SIZE
    ...
}

SECTIONS
{
    .shared :
    {
        _sshared = .;
        *(.shared);
        _eshared = .;
    } > RAM_D3
    ASSERT((_eshared - _sshared) <= RAM_D3_SIZE, "RAM D3 too big")
}

Additional comments/recommendations

1. All the functions, except for core_share_init(), use the return value pattern, i.e., they return -1 when unable to take the lock, and 0 or a positive number for the number of items read, written, or checked.
2. You can use a spinlock for example while (get_from_m4(...) < 0) { ... } or while (put_to_m4(...) < 0) { ... }

Videos with explanations

Checkout the YouTube videos where this library is designed

Contact

This project was created by Adailton Braga. If you have any questions, get in touch by e-mail: adailtonjn68@gmail.com