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Serial Data Output of PLL devices

ADI PLLs are typically programmed using a three-wire serial interface, where the serial programming data is clocked into an internal shift register and is then latched onto the internal data bus on a rising edge of latch enable (see SPI Programming section in relevant datasheet for more details). To help with chip programming debug a Serial Data Output option has been added to several of the ADI PLLs, including the ADF4153, ADF4154, ADF4156, ADF4157, ADF4158 and ADF4159.

Read more in the attached document.

  • Hi,

    To get the data of internal shift register of ADF4153 via MUXOUT, Should I write some value on M3~M1 bits of R Divider register(R1) ?

    At the truth table of MUXOUT, There is no M3~M1 value for specific register.

    For example, If we want to see the Control Register values via MUXOUT during writing, What we should do ?

    When we set the M3~M1 as N DIVIDER OUTPUT, this means that we can see N Divider Register values(total 24bits) ?

    In same way, When we set the M3~M1 as R DIVIDER OUTPUT, this means that we can see R Divider Register values(total 24bits) ?

    If so, We can see only two registers(R0 and R1) via MUXOUT, Right ?

    We don't have our board and EVB, so we only rely on your response.


  • Serial Data Output (SDO) doesn't actually read out the contents of the various registers. It simples pushes the most recently written data back out to the Muxout pin. So, for example, if you just wrote to R2, then with SDO enabled, 23 clock cycles later, the data written to the DATA pin, will start being output on the Muxout pin.

    On the ADF4153, to enable SDO, you need to set R3, DB[6:2] = 0b00110. So, you would program 0x1B to R3. This connects Serial Data Output to Muxout.

    Note: when, you write to R1, it will overwrite the Serial Data Ouput to Muxout setting and connect Muxout to whatever it is set to in the R1 write.

    So, you can read out the setting programmed to any register, but only immediately after it has been written to the PLL.

    Does this make sense?