• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 21 subscribers
  • Views 256 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMX2820: MUXOUT SPI Readback

Joshua Kirkham
Prodigy 10 points
Part Number: LMX2820
Other Parts Discussed in Thread: , LMX2594

I'm trying to read back register settings from an LMX2820 using SPI on a custom board and an LMX2820EVM demo board.

The data sheet indicates that they can be read back through the MUXOUT pin, but is sparse on details. Other forum posts mention the data sheet for the LMX2594 as the source for protocol information for the 2820 as well, which shows MUXOUT behaving as a SPI SDO line.

However, I'm not seeing this behavior on the 2820EVM. Using the default settings in TICS Pro seems to make the chip communicate with 3 wire spi (ie, sending read data out on the SDI pin), but there doesn't seem to be any information in either data sheet about this.

How can I configure the LMX to send its register readback data out of the MUXOUT pin instead of SDI?

  • 0
    TI__Guru* 97050 points

    Hi Joshua,

    Since LMX2820 has dedicated pin for lock detect, MUXOUT is default to SPI SDO output, we don't need to configure a certain register to achieve this goal.