RE: Is CRC32_ENABLED in hardware or software for nrf52832?

TilakL — Tue, 08 Mar 2022 11:23:22 GMT

Thank you for the clarification. That solves my query. I am not sure how to mark your reply as the answer.

RE: Is CRC32_ENABLED in hardware or software for nrf52832?

haakonsh — Tue, 08 Mar 2022 10:06:20 GMT

/**@brief Function for calculating CRC-32 in blocks.
 *
 * Feed each consecutive data block into this function, along with the current value of p_crc as
 * returned by the previous call of this function. The first call of this function should pass NULL
 * as the initial value of the crc in p_crc.
 *
 * @param[in] p_data The input data block for computation.
 * @param[in] size   The size of the input data block in bytes.
 * @param[in] p_crc  The previous calculated CRC-32 value or NULL if first call.
 *
 * @return The updated CRC-32 value, based on the input supplied.
 */
uint32_t crc32_compute(uint8_t const * p_data, uint32_t size, uint32_t const * p_crc);


uint32_t crc32_compute(uint8_t const * p_data, uint32_t size, uint32_t const * p_crc)
{
    uint32_t crc;

    crc = (p_crc == NULL) ? 0xFFFFFFFF : ~(*p_crc);
    for (uint32_t i = 0; i < size; i++)
    {
        crc = crc ^ p_data[i];
        for (uint32_t j = 8; j > 0; j--)
        {
            crc = (crc >> 1) ^ (0xEDB88320U & ((crc & 1) ? 0xFFFFFFFF : 0));
        }
    }
    return ~crc;
}

I've copied the declaration with docs, and the definition of crc32_compute(), as you can see it's a SW implementation.
The radio has a HW CRC block, but it's not available for the CPU to use.