If a SPI port is not enough for your application, you may need a SDIO interface on your STM32. Anyway, you may install App STM32 Finder from STM32-FINDER - STM32 product finder for mobile devices - STMicroelectronics, and select right MCU for your a...
You may need to check firstly if a rising edge was here on nINT pin of RTC. if not, a pull-up may be needed on this pin if it's drive mode is Open Drain.
About USART3 (on PD8&PD9) connected to embedded STLINK, the IO assignment is correct in NUCLEO-H755ZI-Q.ioc as shown below. so if you connect your PC to USB connector CN1 on your board, there no HW connection issue. You may check your FW by open SB17...
With what shown in Analyzer, it seems you are send out data successfully by driving SCK and MOSI, the only thing is no feedback received on MISO which should be driven by ADS. so pls. check MOSI pin of STM32F4 is connected to DIN pin of ADS, and MISO...
