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LMK04821: Delay required after reset?

Damon Beales
Prodigy 10 points
Part Number: LMK04821

Dear Sir / Madam,

What delay is required after pulsing the reset pin before registers can be written via SPI? Does the device reset on the rising edge of RESET?

Same question really, but for SOFT RESET - after setting SOFT RESET in REGISTER0000, what delay is required before further initialisation is done?

Thanks.

Regards,
Damon

  • 0
    TI__Genius 12560 points

    Hi Damon,

    RESET pin or Register write to R0 (0x000) can be used to reset the device. RESET field in R0 to trigger a software reset, which is self-clearing after the minimum assertion time and is equivalent to toggling the RESET pin. Soft reset or reset pulse at pin helps to reset the internal state machines.

    For reference, the RESET pin state must be held high for three internal state machine clock cycles; we run the internal state machine at around 10MHz ± 30%, so worst case hold RESET pin high for around 400ns should guarantee a RESET. We usually recommend 1µs to account for rise/fall time variation in the RESET signal source, line capacitance, etc.

    Thanks!

    Regards,
    Ajeet Pal