I have connected the LCD to 3V power net and the microcontroller to 3.3V power net.
To communicate with the LCD, I need to use SPI interface. So my questions are:
1) As I can see, according to LCD's datasheet, it has only 3 pins of the SPI interface (SCL - clock, SI - serial data, CS). The A0 pin is connected to MCU GPIO. And I see that according to the datasheet the LCD has a command to read the display pixels, so the LCD should send data back to MCU - but on which pin? I assume that the LCD is SPI "slave" device and SI pin is input only. Also, the MCU's SPI2_MOSI pin is route the SI pin. Should I change it because of the LCD's RX?
2) I have found the table below in the MCUs datasheet. I assume that the voltage levels are relevant to the SPI interface too. I'm a little bit confused. An output pin can be TTL and CMOS or can it be configured like a direction of GPIO? How I know if the output pin is CMOS or TTL?
I'm asking this because I want to put logic level translator IC between the LCD and the MCU. And I assume according to the logic levels of the LCD that the LCD is CMOS.
Thank you very much!