SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
In some applications, the SCI can be connected to more than one serial communication device. In such a multiprocessor configuration, several frames of data can be sent to all connected devices or to an individual device. In the case of data sent to an individual device, the receiving devices must determine when the devices are being addressed. When a message is not intended for them, the devices can ignore the following data. When only two devices make up the SCI network, addressing is not needed, so multiprocessor communication schemes are not required.
SCI supports two multiprocessor communication modes which can be selected using COMM MODE bit:
When the SCI is not used in a multiprocessor environment, software can consider all frames as data frames. In this case, the only distinction between the idle-line and address-bit modes is the presence of an extra bit (the address bit) in each frame sent with the address-bit protocol.
The SCI allows full-duplex communication where data can be sent and received using the transmit and receive pins simultaneously. However, the protocol used by the SCI assumes that only one device transmits data on the same bus line at any one time. No arbitration is done by the SCI.