Other Parts Discussed in Thread: LMK04828,
In our design, we are using the LMK04828B (1Nos) and LMX2594RHAR (2Nos) Clock Synthesizer IC's to provide the clock to RFSoC ADC/DAC reference clock and connected through SPI interface.
If the LMK and two LMX IC's are connected from SoC through SPI interface as described in below figure. we are able to do SPI write properly and SPI read is not proper.
When connecting only one device in the SPI line, SPI read back is proper.
While analyzing, few observations are found capture in below.
* SPI MOSI, and CS select are proper and Voh level is 3.16V.
* SPI MISO signal Voh is 3.04V if we are only connecting one device to MISO line
* SPI MISO signal Voh is 1.44V if we are connecting two LMX to MISO line.
* SPI MISO signal Voh is 1.44V if we are connecting one LMX and one LMK to MISO line.
Please let us know, why this voltage misbehaving in the SPI MISO line if we are connecting more than one device in the MISO line. And what is the solution for the same.
