essl_spi_wrdma() function

Send long buffer in segments to the slave through its DMA.

Syntax

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Summary

Declaration

Definition

from essl_spi.h:279

esp_err_t essl_spi_wrdma(spi_device_handle_t spi, const uint8_t *data, int len, int seg_len, uint32_t flags);

Implemented in essl_spi.c:230

Arguments

Argument

Description

spi

SPI device handle representing the slave

data

Buffer for data to send, strongly suggested to be in the DRAM

len

Total length of data to send.

seg_len

Length of each segment, which is not larger than the maximum transaction length allowed for the spi device. Suggested to be multiples of 4. When set < 0, means send all data in one segment (the ``wrdma_done`` will still be sent.)

flags

`SPI_TRANS_*` flags to control the transaction mode of the transaction to send.

Return value

- ESP_OK: success - or other return value from :cpp:func:`spi_device_transmit`.

Notes

This function combines several :cpp:func:`essl_spi_wrdma_seg` and one :cpp:func:`essl_spi_wrdma_done` at the end. Used when the slave is working in segment mode.

Examples

References

from examples

essl_spi_wrdma() function

Syntax

Arguments

Return value

Notes

Examples

References

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