Tool/software:
Hello,
I am trying to debug a problem with LMK04828 which is not responding to SPI commands. I do a simplest write command like the following two examples:
Write 0x1 to register 0x2 to execute power-down, which should result in a visible drop in current draw.
Write 0x4 to register 0x16e which should drive logic 1 to the pin STATUS_LD2.
None of these two commands produce expected behavior.
I assume that doing a single write command eliminates differences between 3-wire and 4-wire SPI, since there would be no response from the SPI slave.
I have checked all power pins, reset (which is de-asserted low), and the three SPI signals: CSn, SCK, SDIO.
The three SPI signals checked with a scope look great, probed close to the pins. Signal integrity, timings, signal levels all look good and I am able to verity that SDIO bit stream looks good.
Is there anything other than power, reset, SPI lines that needs to be controlled in a certain way in order to get the IC to respond to SPI command?
thx.
