duplex (one pointer is NULL) transfers;
+ optionally defining short delays after transfers ... using
- the spi_transfer.delay_usecs setting (this delay can be the
- only protocol effect, if the buffer length is zero);
+ the spi_transfer.delay.value setting (this delay can be the
+ only protocol effect, if the buffer length is zero) ...
+ when specifying this delay the default spi_transfer.delay.unit
+ is microseconds, however this can be adjusted to clock cycles
+ or nanoseconds if needed;
+ whether the chipselect becomes inactive after a transfer and
any delay ... by using the spi_transfer.cs_change flag;