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10.3
SCI3
10.3.1
Overview
Serial communication interface 3 (SCI3) has both synchronous and asynchronous serial data
communication capabilities. It also has a multiprocessor communication function for serial data
communication among two or more processors.
Features: SCI3 features are listed below.
•
Selection of asynchronous or synchronous mode
Asynchronous mode
Serial data communication is performed using the asynchronous method, in which
synchronization is achieved character by character.
SCI3 can communicate with a UART (universal asynchronous receiver/transmitter), ACIA
(asynchronous communication interface adapter), or other chip that employs standard
asynchronous serial communication. It can also communicate with two or more other
processors using the multiprocessor communication function. There are twelve selectable
serial data communication formats.
•
Data length: seven or eight bits
•
Stop bit length: one or two bits
•
Parity: even, odd, or none
•
Multiprocessor bit: one or none
•
Receive error detection: parity, overrun, and framing errors
•
Break detection: by reading the RXD level directly when a framing error occurs
Synchronous mode
Serial data communication is synchronized with a clock signal. SCI3 can communicate
with other chips having a clocked synchronous communication function.
•
Data length: eight bits
•
Receive error detection: overrun errors
•
Full duplex communication
The transmitting and receiving sections are independent, so SCI3 can transmit and receive
simultaneously. Both sections use double buffering, so continuous data transfer is possible in
both the transmit and receive directions.
•
Built-in baud rate generator with selectable bit rates.
•
Internal or external clock may be selected as the transfer clock source.
•
There are six interrupt sources: transmit end, transmit data register empty, receive data register
full, overrun error, framing error, and parity error.