After dividing the signal of VCO with the chip HMC438, the signal of VCO is fed into the VCON VCOP port of HMC984, but after configuring the registers, it is not possible to output the fed signal through GPIO.
However, after I reconfigured the registers, I can output the XREF signal through the GPIO port.
After that I grounded one end of the differential line through a capacitor and fed the other end with a single-ended signal through a signal source, which also could not be successfully output.
I would like to ask what could be the cause?
将VCO的信号用HMC438这个芯片分频之后，送入HMC984的VCON VCOP端口，但是配置完寄存器后，无法将送入的信号通过GPIO输出出来。
但是我重新配置寄存器后，可已经XREF的信号通过GPIO端口是输出出来。
之后我又将差分线的一端通过电容接地，另外一端通过信号源送入单端信号，也无法成功输出。
我想请问一下可能是什么原因呢?
