Agilent Oscilloscope Selection Tip 8 Serial Bus Applications - Application Note 5990-9606EN c20130402 [2] free download

File name Oscilloscope Selection Tip 8_ Serial Bus Applications - Application Note 5990-9606EN c20130402 [2].p

Oscilloscope Selection Tip 8: Serial Bus Applications Part 8 of a 12-part series Tip 8 Select a scope that can trigger on and decode serial buses to help you debug your designs faster. Serial buses such as I2C, SPI, RS232/UART, CAN, etc., are pervasive in many of today's digital and mixed-signal designs. Verifying proper bus communication along with analog signal quality measurements requires using an oscilloscope. Many engineers and techni- cians verify serial bus communication with an oscilloscope using a technique known as "visual bit counting". But this manual method of decoding a serial bus can be time consuming and prone to errors. However, many of today's DSOs and MSOs have optional built-in serial bus protocol decode and triggering capabilities. If your designs include serial Agilent's InfiniiVision 2000, 3000 bus technology, then selecting a scope that can decode and trigger on these buses can be a significant time-saver to help you debug your systems faster. and 4000 X-Series oscilloscopes Most scopes on the market today that have serial bus analysis capabilities utilize software- provide a broad range of serial based decoding techniques. With software-based decoding, waveform and decode-update rates tend to be slow (sometimes seconds per update). This is especially true when using bus analysis options with hard- scopes with deep memory, which is often required to capture multiple packetized serial bus ware-based protocol decoding. signals. And when analyzing multiple serial buses simultaneously, software techniques can make protocol-specific decode update rates even slower. Agilent's InfiniiVision Series oscilloscopes utilize hardware-based decoding to provide virtual real-time updates. Faster decoding with hardware-based technology enhances scope usabil- ity, and more importantly, the probability of capturing infrequent serial communication errors. Figure 1 shows an example of an Agilent 3000 X-Series oscilloscope capturing and decoding a CAN (Controller Area Network) serial bus, which is commonly used in many automotive and industrial machinery applications, including medical diagnostics equipment. Below