The controller is 7920 IC. What are the pins defined when it is working on SPI mode?
We take WG14432A as an example. If we choose SPI mode, connect the PSB to GND first.
WG14432A: PSB Jump as the diagram, we need to open the R10 and make R11 shorted. Then it will become SPI mode. And then, RS becomes CS, R/W becomes SID, and E becomes SCLK.