The Instek DS3-SBD Serial Bus Analysis Software is an optional accessory for use with the GDS-3000 Series Digital Storage Oscilloscopes. The optional serial bus analysis software facilitates the engineer's tasks in testing and manufacturing of the associated products. The serial bus trigger and decode software includes support for 3 common serial interfaces: SPI (4 channel models only), UART and I2C. Each interface is fully configurable to accommodate a wide range of protocol variation. Each input can be displayed as binary or hexadecimal. An event table can also be created to aid in debugging.

Each serial bus type (UART, I2C, SPI) can have an event table saved containing each bus event as a .CSV file. An event is defined as the data on the bus when a Stop or End of Packet (UART) is encountered. The data associated with each event and the time of each event is recorded.

The UART serial bus software is designed to decode RS232 and other common RS-232 variants such as RS-422, RS-485. The software configuration is also flexible enough to decode the many proprietary protocols based on RS-232.

The I2C bus is a 2 wire interface with a serial data line (SDA) and serial clock line (SCLK). The I2C protocol supports 7 or 10 bit addressing and multiple masters. The decode software will trigger on any of the following conditions: a start/stop condition, a restart, a missing acknowledge message, Address, Data or Address & Data frames. The I2C trigger can be configured for 7 or 10 bit addressing with the option to ignore the R/W bit as well as triggering on a data value or a specific address and direction (read or write or both).

The serial peripheral interface (SPI) is a full duplex 4 wire synchronous serial interface. The 4 signals lines: Serial clock line (SCLK), slave select (SS), Master output/slave input (MOSI, or SIMO) and the Master input/slave output (MISO, or SOMI). The word size is configurable from 8, 16 or 32 bits. The SPI triggers on the data pattern at the start of each framing period. This bus is only available on 4 channel models.