Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
21 years ago

External Memory

I may have an application that needs external memory devices on the same bus. It includes FLASH, SRAM, EEPROM, and other memory mapped devices. This is just an excersize, so we'll keep the dat...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
21 years ago

Rppolicy,

Not quite; what you want is to use the "Interface to User Logic". This is for importing your own peripherals as well as just sprouting pins to the outside world.

There are two tricks to this:

1. Be sure to specify your data bus as type "inout" -- this tells SOPCB that the interface is bi-dir and needs to be mastered by the tri-state bridge; you can then hook up your new interface to the same tri-state master as your CFI flash.

2. Use the "Shared" checkbox for any pins on the tri-state bus that will be common to multiple devices. For example, read, write, byte enable, and address are very often shared. Devices will usually have an "private" (non-shared) chipselect; just share the pins in such a way that agrees with how you're designing, or planning to design, your board.