Software Flow Control; Auto Baud Rate Detection - Samsung S3C2500B User Manual

SERIAL I/O (HIGH-SPEED UART)
RXD
RTS
CTS
RXD
Pin Signal
DCD
RXD
Internal
Signal

14.4.3 SOFTWARE FLOW CONTROL

Software can control High-Speed UART by control characters. High-Speed UART compares received data with
control characters, and if they are identical, it sets "1" at state bit (CCD:HUSTAT[5]) and generates interrupt
which masked by Interrupt enable register.

14.4.4 AUTO BAUD RATE DETECTION

To use Auto Baud Rate Detection, Set ABB(AutoBaud rate Boundary), ABT(AutoBaud rate Table) Register and
Auto Baud Detect bit(AUBD:HUCON[6]), When RXD level is low, High-Speed UART counts low-level of start
signal ( 'A' ) and rewrites counting value of low-level by comparing ABB, ABT Register. This automatically
corrects Baud Rate(CNT0 and CNT1)
14-26
Start Bit
Figure 14-17. Normal Received Rx Data
Start Bit
Start Bit
Figure 14-18. DCD Lost During Rx Data Receive
Data Region
Data Region
S3C2500B
Stop Bit
Stop Bit