(Links are component datasheets or application notes.) I have a project using the STM32H series MCU that requires external SDRAM for data storage. Due to the size, the PCB is going to cost near $1,000 to fab and so I'd like to make sure that the design is correct before sending it to the board house. I've found several application notes on the STM32H; however, none seem to answer all of my questions satisfactorily.
The RAM chip I selected based on price and memory size, but I'm not sure about compatibility with the MCU as I'm new to the subject. Since the data being stored will be MIDI files, I chose the 1Gb (32M x 32) RAM chip W94AD2KBJX5I. As I understand it, MIDI files are made up of 32 bit chunks and so would require a 32 bit data bus? My concern with this chip is that it shows a `CLK` pin and a `!CLK` pin and the MCU app notes (pages 52-53) I've found only show a connection to `CLK`. Is the inverted pin left floating, grounded, or am I missing something here? I've also noted that there seem to be a pin or two on the STM32H that I don't see in the app notes but are listed in the MCU datasheet as part of the Flexible Memory Controller (FMC) such as the FMC_NWAIT pin. Does anyone with experience interfacing external SDRAM to the STM32H series MCUs mind giving me a rundown of this?
The RAM chip I selected based on price and memory size, but I'm not sure about compatibility with the MCU as I'm new to the subject. Since the data being stored will be MIDI files, I chose the 1Gb (32M x 32) RAM chip W94AD2KBJX5I. As I understand it, MIDI files are made up of 32 bit chunks and so would require a 32 bit data bus? My concern with this chip is that it shows a `CLK` pin and a `!CLK` pin and the MCU app notes (pages 52-53) I've found only show a connection to `CLK`. Is the inverted pin left floating, grounded, or am I missing something here? I've also noted that there seem to be a pin or two on the STM32H that I don't see in the app notes but are listed in the MCU datasheet as part of the Flexible Memory Controller (FMC) such as the FMC_NWAIT pin. Does anyone with experience interfacing external SDRAM to the STM32H series MCUs mind giving me a rundown of this?