ESSL: Abbreviation for ESP Serial Slave Link, the component described by this document.
Master: The device running the esp_serial_slave_link component.
ESSL device: a virtual device on the master associated with an ESP slave device. The device
context has the knowledge of the slave protocol above the bus, relying on some bus drivers to
communicate with the slave.
ESSL device handle: a handle to ESSL device context containing the configuration, status and
data required by the ESSL component. The context stores the driver configurations,
communication state, data shared by master and slave, etc.
The context should be initialized before it is used, and get deinitialized if not used any more. The
master application operates on the ESSL device through this handle.
ESP slave: the slave device connected to the bus, which ESSL component is designed to
Bus: The bus over which the master and the slave communicate with each other.
Slave protocol: The special communication protocol specified by Espressif HW/SW over the bus.
TX buffer num: a counter, which is on the slave and can be read by the master, indicates the
accumulated buffer numbers that the slave has loaded to the hardware to receive data from the
RX data size: a counter, which is on the slave and can be read by the master, indicates the
accumulated data size that the slave has loaded to the hardware to send to the master.