How to use flexible external memory controller bus with external FPGA as a memory device?

[stack_shailesh]

Dear Sir, 

We are using stm32mp135f processor on our custom board. We want to interface flexible external memory controller bus with an external FPGA device. How this can be achieved? Are there any reference or example that you can provide? Is it possible to connect FPGA as an external device?

[PatrickF]

Hi @stack_shailesh 

yes, you could connect an FPGA to the FMC.

Usually, the FPGA need to emulate an SRAM async interface to expose FPGA memory mapped registers/memories.

Then there is STM32MP1 memory map range directly accessible by your Linux driver or else.

Please have a look to this example with a external Ethernet PHY connected to FMC, which could be seens a similar than FPGA use case:  https://wiki.st.com/stm32mpu/wiki/FMC_device_tree_configuration#DT_configuration_of_the_external_bus_interface_controller_-28board_level-29

Regards