Dropping Legacy Terminology

Binho documentation, Mission Control 3 and our SDKs use controller and target for the two roles on a bus. These are the terms of the current I2C and I3C specifications.

Bus	Legacy terms	Terms we use	Source
I2C	Master / Slave	Controller / Target	NXP UM10204 I2C-bus specification and user manual, Rev. 7.0 (1 October 2021)
I3C	Master / Slave	Controller / Target	MIPI Alliance I3C and I3C Basic specifications
SPI	Master / Slave	Controller / Target (peripheral)	OSHWA resolution on SPI signal names
1-Wire	Master / Slave	Host / Device	Analog Devices (formerly Maxim Integrated) 1-Wire documentation

Note

Older datasheets, and some of our older pages for the Binho Nova and Mission Control 2, still use the legacy terms. They mean the same roles: master is the controller, slave is the target.

SPI Signal Names

Legacy name	Current name	Meaning
MOSI (Master Out, Slave In)	SDO on the controller, SDI on the target	Data from the controller to the target
MISO (Master In, Slave Out)	SDI on the controller, SDO on the target	Data from the target to the controller
SS (Slave Select)	CS (Chip Select)	Selects the target. Usually active low, often drawn C̅S̅.
SCK	SCK (unchanged)	Clock, driven by the controller

SDO and SDI are named from the point of view of the device they are on. Many datasheets and tools, including the SPI tool in Mission Control 3, still label the data lines MOSI and MISO.