I'm planning to interface an FPGA to a STM32F29/439 via the FSMC (Flexible Static Memory Controller). To save pins I would like to use the address/data multiplexing feature. Thus according to the datasheet for 16-bit mode I have multiplexed signals AD[1..16]
and control lines nADV
, nWE
, nOE
and nEN
.
Now I only need 8-bit data width but still need at least 10-bit wide addresses, leading to multiplexed signals AD[1...8]
, non-multiplexed high address bits A[9..10]
plus usual control lines. Since this assymetric case is not mentioned explicitly in the datasheet I ask whether someone can share some experience.
Clarification: I'm using a STM32F429 but in general this applies to all STM32F4 with FSMC. I think that the NOR-Flash interface would be most appropriate but unfortunatley the datasheet only mentions 16-bit memory data size, albeit without saying that 8-bit mode is unavailable for NOR Flash.