According to http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1031/LN775/PF216846,

All STM32F1xx-series MCUs (and up) "offer standard communication interfaces (up to two I2Cs, three SPIs, one HDMI CEC, up to three USARTs and 2 UARTS)".

Is there a possibility to use more than one SPI line at same time to construct some kind of custom high-speed bus?


  • \$\begingroup\$ Well, there are memory chips, etc. that use 2- and 4-lane SPI for greater throughput, but you can't just combine multiple single-lane controllers to get the same result, at least not easily. How much throughput do you need? A single SPI can run at up to 10-20 MHz easily, and with three controllers, you can have them all running at the same time to different devices. \$\endgroup\$
    – Dave Tweed
    Mar 25, 2014 at 15:49
  • \$\begingroup\$ Not sure how you would wire it up, but certainly its possible to use multiple SPI bus's in parallel to send more data, but I would advise against it since it could be very problematic. Instead, think about what data rate you really need to use. Many times you can use 1 SPI bus to send data at >1 Mbits/second which is sufficient for most needs. \$\endgroup\$
    – Seidleroni
    Mar 25, 2014 at 15:49
  • \$\begingroup\$ Beyond the (quite fast) capabilities of the standard SPI bus, I'd wonder what an STM32 could do with that much data arriving/departing that quickly? Using standard parallel IO ports would seem the logical thing, like RAM buses with N data lines and N address/control lines. \$\endgroup\$
    – John U
    Mar 25, 2014 at 18:07
  • \$\begingroup\$ Possible, yes. What's your actual purpose though? \$\endgroup\$
    – Passerby
    Mar 25, 2014 at 23:56
  • \$\begingroup\$ The actual purpose is to build a maximum speed external interface for STM32-F1XX chips as most basic and hence the cheapest in the line. There's also FSMC (emcu.it/STM32/STM32-TFT/STM32-TFT.html) module in models with more pins, but i`m not sure it's the fastest interface possible. \$\endgroup\$
    – user37741
    Mar 26, 2014 at 17:01


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