[SPI Slave] some problems about SPI transactions

[paul719]

I use esp32 as a spi slave device, and select mode 3(CPOL=1 CPHA=1) on both side.

Code: Select all

spi_slave_interface_config_t slvcfg = {
        .mode = 3,
        .spics_io_num = GPIO_SPI2_CS,
        .queue_size = 3,
        .flags = 0,
        .post_setup_cb = spi2_post_setup_cb,
        .post_trans_cb = spi2_post_trans_cb
    };

BUT this spi configuration is invalid for MISO. It seems like working on mode 2(CPOL=1 CPHA=0)
We captured the waveform through logic analyzer.

slave_mode3.png (154.45 KiB) Viewed 2327 times

Who knows why the waveform is not match configuration?