A3700_SPI_INT_STAT_REG
spireg_write(a3700_spi, A3700_SPI_INT_STAT_REG, ~0U);
cause = spireg_read(a3700_spi, A3700_SPI_INT_STAT_REG);
spireg_write(a3700_spi, A3700_SPI_INT_STAT_REG, cause);