Is there an easy way to select from multiple external RAM chips with EMIF | Cypress Semiconductor
Is there an easy way to select from multiple external RAM chips with EMIF
I was enthusiastic when I saw that the PSoC5 LP parts have working EMIF controllers, as I really like the flexibility that the PSoC parts provide compared to normal microcontrollers. I have a project right now that I would like to use a PSoC5 LP on, but I need to attach multiple memories to it - specifically a 8Mbit (512kx16) async SRAM and an FPGA with an async SRAM-like interface. It would be nice if these were memory mapped together such that a DMA could be set up to copy data from the FPGA to the SRAM and vice-versa.
The trouble is that there doesn't appear to be a way to use the address lines to selectively enable the parts. Ordinarily, I would just drop a bit of logic on a the high address line to control which part gets the CEn signal, and I can do it here, but it seems like there should be some way to do this internally. Other than routing the MSB of the address bus back in on another pin, is there a way to do this?