Hi.
I have a problem to interface with AMC7812.
AMC7812 is connected with STM32 MCU with SPI interface.
First of all, I want to read Device ID register(0x6C). which is read-only and reset value of 0x1220.
After 100ms after power on, I made a 24 bit READ sequence(0xEC-0x00-0x00) on SDI and repeated it for every 500ms.
Returning SDO looks like some random values.
Attached images are captured SPI signal.
Ch1 - nCS, Ch2 - SCLK, Ch3 - SDO(MISO), Ch4 - SDI(MOSI)
I can see 3 types of SDO sequence. But the value sets are changing over power cycle.
Here is SCH I made.
In the SCH, AVDD/DVDD is 5V, but attached scope images are with 3.3V AVDD/DVDD. Result is same.
Can anybody advise me?
Best Regards,
Hyunwoo Park.