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hmc834 BIST



How do I use the BIST feature of the HMC834?




  • The HMC834 includes some functional BIST:

    • force charge pump output voltage high, low or mid rail (Reg 0x0B[11:9])
    • short phase detector inputs (Reg 0x0B[3])
    • route internal nodes to SDO pin (Reg 0x0F[4:0])

    and a digital signature generator to verify DSM logic. 

    The digital signature is generated by performing a soft reset (Reg 0x00=0x20) then configuring the part as usual but with the following changes:

    1. set R >= 10 
    2. enable BIST (Reg 0x06[20:18]=001b)
    3. set Reg 0x0A[14:13]=01b, Reg 0x0A[7:6]=01b and Reg 0x0A[15]=1
    4. set  N (Reg 0x03 and Reg 0x04) to any valid number.  BIST will start after writing Reg 0x4.  Each N value generates a unique signature.
    5. Read the signature from Reg 0x013 after BIST busy=0 and compare to a known good part.
  • Hi


    Thanks for your help.

    One question: Is the soft recet mandatory? this means that whenever I weant to perform the DSM test I have to re-init the HMC384 device.