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RM48L950: 20 SPI Slave device

Part Number: RM48L950


I am using RM48L950 in my project for to control 20 SPI slave device. From datasheet I understand it support 5 SPI. So I am going to share each SPI  MISO,MOSI and CLK lines for 4 slave devices with separate chip select(So total 5*4=20). Refer image for reference(3 only showing in image).

So I need total 20 Chip select for to control 20 Slave devices, in that each SPI data and CLK lines sharing across 4 slave devices.

Kindly let me know is there any issue while connecting 20 SPI slaves like this configuration?

Also let me know the maximum distance it can handle along with throughput?

Is there any other option for to control 20 Slave devices using SPI(Any Switch mechanism)?

Kindly reply

Warm regrads,

Monisha OM

  • Hello Monisha,

    You can use GIO and N2HET signals as the SPI chip-selects, or you can use a multiplexors to control more slave devices.

    The SPI is designed for short-distance on-board communication. The distance is dependent of signal layout on your PCB, the SPI frequency, etc. If you have to extend the transmission distance, please refer to this appnote: