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Serial bus analysis
R&S
®
RTM3000
277
User Manual 1335.9090.02 ─ 09
Figure 13-16: Decoded I2C signal with applied label list and zoom on second frame
13.4
UART / RS232 (option R&S
RTM-K2)
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13.4.1
The UART / RS232 interface
The Universal Asynchronous Receiver/Transmitter UART converts a word of data into
serial data, and vice versa. It is the base of many serial protocols like of RS-232. The
UART uses only one line, or two lines for transmitter and receiver.
Data transfer
The data is transmitted in symbols, also referred to as words or characters. Each sym-
bol consists of a start bit, several data bits, an optional parity bit, and one or more stop
bits. Several symbols can form a frame, or package. The end of a frame is marked by
a pause between two symbols.
[Data8] [Parity] Stop
[Data7]
[Data6]
[Data5]
Data4
Data3
Data2
Data1
Data0
Start
Figure 13-17: Bit order in a UART word (symbol)
UART / RS232 (option R&S
RTM-K2)