Introduction to SP259 series logic analyzers
What are the SP259 series?
SP259 series logic analyzers and protocol decoders offer in-depth analysis of logic signals and protocols with 250MHz (4ns) timing resolution. The 9-channel operation allows 8-bit parallel data to be captured along with a clock or strobe signal. SP259 range of logic analyzers is composed of two devices, SP259 and SP259i. Both offer 9 logic inputs, but SP259i integrates industrial receivers for CAN, LIN, RS232 and RS485 buses.
Below is a top view of the SP259i Logic Analyzer:
Principle of operation
SP259 Series logic analyzers connect to a computer via a USB cable. A free software - called ScanaStudio - is used to configure the device and display captured signals. The software can also be used to further analyze the captured samples by decoding protocols like I2C, SPI or UART.
Embedded memory vs streaming
USB-based logic analyzers (ones that don’t have a display and rely on a computer for that matter) usually operate according to one of two schemes:
- Using an embedded memory to store captured samples. Samples are later downloaded at a slower speed via the USB interface. This has the advantage of not being limited by USB transfer rate but has the disadvantage of limited embedded memory.
- Streaming captured samples over the USB connection, at the maximum possible speed. While this offers the advantage of virtually unlimited memory (only limited by the host computer’s memory), it has the disadvantage of limiting the sampling rate to the USB’s throughput.
SP259 combines the advantages of both streaming and embedded memory techniques. An embedded 1Gb HyperRAM memory stores captured and compressed samples at 4Gbps, while a USB interface transfers the data simultaneously, effectively emptying the embedded memory and making more room for new samples. This results in a logic analyzer that can capture dozens of minutes of logic signal activity on 9 channels at 250 MSPS.
The diagram below shows the flow of sampled signals:
SP259 series logic analyzers are perfectly adapted for demanding applications, where it is needed to capture logic signals with maximum time resolution on all 9 channels.
- Embedded systems debugging
- Research and Education
- Serial protocols analysis, like I2C, SPI, UART or 1-Wire (non-exhaustive list)
- Industrial bus analysis: RS232, RS485, CAN, LIN
- ADC diagnostic
On top of standard logic analysis, the industrial version (SP259i) can be used to analyze industrial buses. Furthermore, one can use both the industrial inputs and logic inputs to capture the signals before and after an onboard transceiver. This can help characterize a system like propagation delays or transceiver intermittent failures.
SP259 series logic analyzers ship with the following accessories:
- USB cable 1M (USB3.0 micro-B to A)
- 10 Logic probes (9 signals + 1 ground)
- 5 Pluggable terminal blocks, Wurth reference 691361100003 or equivalent (for SP259i version only)
- Two SMA anti-dust covers
SP259(i) logic analyzer has the following ports and interfaces:
- Status LED
- 9-CH logic probes input
- Trigger OUT SMA connector
- Trigger IN SMA connector
- USB (micro-B) port.
- Industrial port (only on the industrial version)
For detailed timing and DC characteristics, power consumptions and input characteristics, please download the latest version of the datasheet
SP259 series device drivers
SP259 devices uses an USB3 interface IC IC from FTDI CHip, namely the FT601 that requires D3XX drivers.
The latest D3XX drivers can be downloaded here: https://ftdichip.com/drivers/d3xx-drivers/
SP259 LED indications
SP259 status led can either be Off, White, Orange or blinking.
|Device not powered (not connected to a USB port)
|Device connected to USB port but not correctly configured
|Device connected to USB port and correctly configured
|Activity (logic state change) is detected on one or more of the logic channels