I have to interface a uc to a ADF7020-1 and I want use adf7020-1 as master and uc as slave in 3-wire spi mode. adf7020-1 have txrxdata that interfacing with uc(it has mosi and miso pins). how did connect 3-wire SPI into uc? do need isolate mosi and miso pins with diod? Can i Short MISO and MOSI? please help me thanks

short miso and mosi to interface with uc

Figure 36

Data Interface

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    \$\begingroup\$ I don't think the ADF7020 is designed to be a SPI master. Better use your uc as master. \$\endgroup\$ Commented Dec 28, 2018 at 13:04
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    \$\begingroup\$ Indeed. Looking at the datasheet, SCLK is an input. Therefore, it cannot be the SPI master. \$\endgroup\$
    – DoxyLover
    Commented Dec 28, 2018 at 14:22

1 Answer 1


The ADF7020-1 has two digital interfaces.

enter image description here

DATA CLK and DATA I/O are for data to be sent or received on the RF link (0.15 to 200 kbps). This isn't an SPI interface. You need to connect this to something that can continuously stream data at the rate of your RF link. If you are connecting this to a micro, you probably want these pins connected to GPIOs, and DATA CLK triggering a high-priority interrupt (based on a very quick look at the datasheet).

On page 26 in the datasheet, they say there are drivers available for a couple of ADI microcontrollers. Even if you aren't using these devices, it might be worth looking at the code they provide for hints on how to program your micro.

SLE, SCLK, SDATA, and SREAD are an SPI interface (as far as I can tell from a quick read of the datasheet). SDATA would connect to MOSI and SREAD connects to MISO. I don't see any reason you should want to connect MOSI and MISO to each other.

  • \$\begingroup\$ Thank's for taking the time Please take a look at the photos in my edit. In mode tx, rate of clh about 11MHZ and in mode rx about 26KHZ. what pins of uc select for interface with CLKDATA and TXRXDATA? I think spi(clk of spi) is the best way. \$\endgroup\$
    – Pouria
    Commented Dec 30, 2018 at 21:09

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