STM32F4 FSMC 8-bit Data / 10-bit address

[arne]

Posted on November 12, 2014 at 19:08

I'm planning to use the FSMC to memory-map registers of a FPGA. To save pins I would like to use multiplexing between data and address lines. Now, I need only a 8-bit data bus width but would like to address more than 2^8 bytes. This essentially means that the first 8 address/data lines are multiplexed while the upper address lines are not. Is that possible? How would I configure the FSMC to use 8-bit data width but 10-bit addressing?

#fsmc

[waclawek.jan]

Posted on November 13, 2014 at 22:20

The FSMC doesn't care about how many addresses do you physically connect. Simply don't map the higher address pins to GPIOs. You'd need to latch all 10 addresses, unless you want to use A16 up instead of A8 up, i.e. a discontinuous address space.

JW